阅读说明：本技术 一种服用阻燃聚酯纤维及其制备方法 (Flame-retardant polyester fiber for clothes and preparation method thereof ) 是由 尹立新 沈建根 张元华 王丽丽 王雪 杨超明 于 2020-12-29 设计创作，主要内容包括：本发明涉及一种服用阻燃聚酯纤维及其制备方法,将改性聚酯经固相缩聚增粘后纺丝卷绕制得服用阻燃聚酯纤维；改性聚酯的制备方法为：将对苯二甲酸、乙二醇、2,6-吡啶二甲酸、阻燃剂2-羟乙基苯基次磷酸和氯化锌混合均匀后先后进行酯化反应和缩聚反应得到改性聚酯；制得的服用阻燃聚酯纤维的聚酯链段包括对苯二甲酸链段、乙二醇链段、阻燃剂2-羟乙基苯基次磷酸链段和2,6-吡啶二甲酸链段,且不同聚酯链段的2,6-吡啶二甲酸链段之间经Zn～(2+)配位；对苯二甲酸链段、2,6-吡啶二甲酸链段和阻燃剂2-羟乙基苯基次磷酸链段的摩尔比为1:0.06～0.08:0.03～0.05；2,6-吡啶二甲酸链段参与配位的有羰基上的O原子和吡啶上的N原子。本发明通过配位提高聚酯的热降解温度,从而达到有效降低熔滴的目的。(The invention relates to a clothing flame-retardant polyester fiber and a preparation method thereof, wherein modified polyester is tackified by solid phase polycondensation and then spun into a yarn coil to be wound to obtain the clothing flame-retardant polyester fiber; the preparation method of the modified polyester comprises the following steps: uniformly mixing terephthalic acid, ethylene glycol, 2, 6-pyridinedicarboxylic acid, flame retardant 2-hydroxyethyl phenylphosphinic acid and zinc chloride, and then carrying out esterification reaction and polycondensation reaction in sequence to obtain modified polyester; the prepared polyester chain segment for the flame-retardant polyester fiber comprises a terephthalic acid chain segment, an ethylene glycol chain segment, a flame retardant 2-hydroxyethyl phenylphosphinic acid chain segment and a 2, 6-pyridinedicarboxylic acid chain segment, and Zn is arranged between the 2, 6-pyridinedicarboxylic acid chain segments of different polyester chain segments 2+ Coordination; the molar ratio of the terephthalic acid chain segment, the 2, 6-pyridinedicarboxylic acid chain segment and the flame retardant 2-hydroxyethyl phenylphosphinic acid chain segment is 1: 0.06-0.08: 0.03-0.05;the 2, 6-pyridinedicarboxylic acid segment is coordinated by an O atom on the carbonyl group and an N atom on the pyridine. The invention improves the thermal degradation temperature of the polyester through coordination, thereby achieving the purpose of effectively reducing molten drops.)

1. A flame-retardant polyester fiber for clothing, which is characterized in that: the polyester chain segment for the flame-retardant polyester fiber comprises a terephthalic acid chain segment, an ethylene glycol chain segment, a flame retardant 2-hydroxyethyl phenylphosphinic acid chain segment and a 2, 6-pyridinedicarboxylic acid chain segment, and Zn is arranged between the 2, 6-pyridinedicarboxylic acid chain segments of different polyester chain segments²⁺Coordination;

the molar ratio of the terephthalic acid chain segment, the 2, 6-pyridinedicarboxylic acid chain segment and the flame retardant 2-hydroxyethyl phenylphosphinic acid chain segment is 1: 0.06-0.08: 0.03-0.05;

the 2, 6-pyridinedicarboxylic acid segment is coordinated by an O atom on the carbonyl group and an N atom on the pyridine.

2. The fiber of claim 1, wherein the 2, 6-pyridinedicarboxylic acid segments of different polyester segments are Zn-doped²⁺The coordination structure formed by coordination is as follows:

3. the flame-retardant polyester fiber for clothing as claimed in claim 1, wherein the 5% thermal weight loss temperature of the flame-retardant polyester fiber for clothing is 425-432 ℃, and the maximum decomposition temperature is 467-488 ℃;

the limit oxygen index of the flame-retardant polyester fiber is more than 30 percent, the flame-retardant time is not needed, and the number of the molten drops in 15s is 0.

4. The flame retardant polyester fiber for clothing according to claim 1, wherein the performance index of the flame retardant polyester fiber for clothing is as follows: the fineness is 75-100 dtex, the breaking strength is more than or equal to 3.5cN/dtex, the elongation at break is 35.0 +/-3.0%, the deviation rate of linear density is less than or equal to 0.7%, the CV value of the breaking strength is less than or equal to 6.0%, the CV value of the elongation at break is less than or equal to 10.0%, the CV value of yarn evenness unevenness is less than or equal to 2.00%, the boiling water shrinkage is 7.5 +/-0.5%, and the oil content is 0.90 +/-0.20%.

5. A preparation method of the flame-retardant polyester fiber for clothes is characterized by comprising the following steps: spinning and winding the modified polyester after solid-phase polycondensation and tackifying to obtain the clothing flame-retardant polyester fiber;

the preparation method of the modified polyester comprises the following steps: uniformly mixing terephthalic acid, ethylene glycol, 2, 6-pyridinedicarboxylic acid, flame retardant 2-hydroxyethyl phenylphosphinic acid and zinc chloride, and then carrying out esterification reaction and polycondensation reaction in sequence to obtain the modified polyester.

6. The method for preparing the flame-retardant polyester fiber for clothes according to claim 5, wherein the modified polyester is prepared by the following steps:

(1) performing esterification reaction;

preparing terephthalic acid, ethylene glycol, 2, 6-pyridinedicarboxylic acid and flame retardant 2-hydroxyethyl phenyl hypophosphorous acid into slurry, adding a catalyst, a stabilizer and zinc chloride, uniformly mixing, pressurizing in a nitrogen atmosphere to perform esterification reaction, wherein the pressurizing pressure is normal pressure to 0.3MPa, the temperature of the esterification reaction is 250-260 ℃, and the termination condition of the esterification reaction is as follows: the distilled water amount in the esterification reaction reaches more than 90 percent of a theoretical value;

(2) performing polycondensation reaction;

after the esterification reaction is finished, starting the polycondensation reaction in a low vacuum stage under the condition of negative pressure, stably pumping the pressure in the low vacuum stage from normal pressure to below 500Pa in 30-50 min at the reaction temperature of 250-260 ℃ for 30-50 min, then continuously pumping the vacuum to perform the polycondensation reaction in a high vacuum stage, further reducing the reaction pressure to below 100Pa, controlling the reaction temperature of 270-282 ℃ and the reaction time of 50-90 min, and obtaining the modified polyester.

7. The method of claim 6, wherein the modified polyester has a number average molecular weight of 20000 to 25000.

8. The method for preparing the flame-retardant polyester fiber for clothes according to claim 6, wherein the molar ratio of terephthalic acid, ethylene glycol, 2, 6-pyridinedicarboxylic acid and flame retardant 2-hydroxyethyl phenylphosphinic acid is 1: 1.2-2.0: 0.06-0.08: 0.03-0.05, and the addition amount of the catalyst and the stabilizer is 0.01-0.05 wt% and 0.01-0.05 wt% of the addition amount of terephthalic acid, respectively; the adding amount of the zinc chloride is 0.9-1.5 mol% of the adding amount of the terephthalic acid.

9. The method of claim 8, wherein the catalyst is antimony trioxide, ethylene glycol antimony or antimony acetate, and the stabilizer is triphenyl phosphate, trimethyl phosphate or trimethyl phosphite.

10. The method for preparing the flame-retardant polyester fiber for clothes according to claim 9, wherein the spinning process parameters are as follows:

spinning temperature: 280-290 ℃;

cooling temperature: 20-25 ℃;

network pressure: 0.20 to 0.30 MPa;

a roll speed: 2200-2600 m/min;

first roll temperature: 75-85 ℃;

two roll speed: 3600-3900 m/min;

temperature of the two rolls: 135-165 ℃;

winding speed: 3550-3840 m/min.

Technical Field

The invention belongs to the technical field of polyester fibers, and relates to a flame-retardant polyester fiber for clothing and a preparation method thereof.

Background

The polyester has high symmetry of molecular chain structure and rigidity of benzene ring, so that the product has good machining performance, chemical corrosion resistance, antimicrobial corrosion resistance and the like, and is widely applied to various fields of fibers, films, plastic products and the like due to the advantages of relatively low price, easy recovery and the like. However, polyester fabrics are flammable and drip after combustion, causing irreparable loss to the safety of people and property, and limiting the application fields of polyester fabrics in military uniforms, protective clothing and the like. Therefore, domestic researchers have been working on flame retardant studies of polyester fabrics.

At present, the problem of poor flame retardant property of polyester fiber is mainly that the flame retardant capability of the polyester fiber is improved by a flame retardant modification mode. Common flame retardant modifiers include halogen flame retardants, phosphorus flame retardants, inorganic flame retardants, and organic-inorganic hybrid flame retardants. The organic-inorganic hybrid flame retardant is a flame-retardant modified material with a wide application range at present, multiple flame retardance can be realized through the synergistic effect of organic components and inorganic components in the combustion process of the polyester fiber, however, the inorganic components of the currently adopted hybrid flame retardant are high in addition amount, poor in dispersion and low in efficiency, and the processing and forming of the flame-retardant polyester fiber are greatly limited due to the problems.

However, inhibiting or slowing down the melt dripping performance of flame retardant polyesters has become a recognized technical problem in the research of flame retardant polyesters. At present, the flame retardant used for polyester is mainly a phosphorus flame retardant, and one of the ways of the action mechanism of the flame retardant is to promote high-temperature molten drops or flame molten drops to be generated in the combustion process of a polymer so as to achieve the effect of reducing the temperature of a combustion surface or keeping away from open fire, thereby generating the flame retardant effect of a condensed phase. In the case of fire and a large number of documents, it can be found that the melting and dropping of the flame-retardant polyester can take away a large amount of heat generated during the combustion of the flame-retardant polyester, so as to prevent the combustion of the flame-retardant polyester, but because the dropping temperature is high or flame still exists, the harm of scald or secondary fire is easily caused, and the like, therefore, the phosphorus flame-retardant polyester and the products thereof have certain defects in the aspects of labor protection clothes, infant clothes, military combat uniform and the like.

Therefore, the research on the clothing flame-retardant polyester fiber with excellent melting and dropping resistance is of great significance.

Disclosure of Invention

The invention provides a clothing flame-retardant polyester fiber and a preparation method thereof, aiming at solving the problem that the improvement of the flame-retardant property of polyester in the prior art has certain limitation.

In order to achieve the purpose, the invention adopts the following scheme:

the polyester chain segment for wearing the flame-retardant polyester fiber comprises a terephthalic acid chain segment, an ethylene glycol chain segment, a flame retardant 2-hydroxyethyl phenylphosphinic acid chain segment and a 2, 6-pyridinedicarboxylic acid chain segment, and Zn is arranged between the 2, 6-pyridinedicarboxylic acid chain segments of different polyester chain segments²⁺Coordination;

the molar ratio of the terephthalic acid chain segment, the 2, 6-pyridinedicarboxylic acid chain segment and the flame retardant 2-hydroxyethyl phenylphosphinic acid chain segment is 1: 0.06-0.08: 0.03-0.05;

the 2, 6-pyridinedicarboxylic acid segment is coordinated by an O atom on the carbonyl group and an N atom on the pyridine.

In practical application, because molecular chains are linearly arranged, and chain segments of the polyester are not supported by firmer cross-linking nodes, the macromolecular movement is inevitably influenced when the polyester is heated. The cross-linking points can be chemical cross-linking points or physical cross-linking points, wherein the chemical cross-linking structure forms stable intramolecular chemical bonds, and the physical cross-linking structure is an ionic bond, a coordination bond and the like.

The metal-ligand coordination interaction enhances the molecular interaction of the macromolecular chain segment, impeding the movement of the polymer chain. In the zinc chloride doped polyester fiber, two pyridine ligands are contained around one core of Zn (II), and the coordination structure of the two intermolecular pyridine ligands tends to promote the aggregation of polymer chains. The thermal degradation temperature of the polymer into which zinc ions are introduced is further increased.

As the ligand, most of the ligands generally used are carboxylic acids, nitrogen-containing ligands: carboxyl groups in the carboxylic acid ligand can have stronger coordination and chelating capacity with metal ions; the 2, 6-pyridinedicarboxylic acid belongs to a nitrogen heterocyclic aromatic carboxylic acid ligand, integrates the advantages of the aromatic carboxylic acid ligand and the nitrogen heterocyclic ligand, and the pyridine heterocyclic can be combined with various metals to form more metal complexes due to good electron donating and electron accepting capabilities; it has a closed large pi bond, an N atom sp²The orbit has a pair of lone pair electrons, which belongs to a non-centrosymmetric structure, conjugated electron supply and electron withdrawing groups, and the intramolecular energy can generate charge transfer, so that the coordination ability is strong, and meanwhile, the stability of the complex is increased by the conjugation effect.

The reason why the zinc ion forms a four-coordinate compound is that the energy of 1 s orbital and 3 p orbitals of the compound is similar, so that the compound can be hybridized to form sp³The hybrid orbitals can accommodate lone-pair electrons of the ligand, and are easy to coordinate with elements such as nitrogen, oxygen and the like to form stable complexes so as to form tetra-coordinated compounds.

As a preferred technical scheme:

as described above, in a flame retardant polyester fiber for clothes, Zn is added between 2, 6-pyridinedicarboxylic acid segments of different polyester segments²⁺The coordination structure formed by coordination is as follows:

the flame-retardant polyester fiber for clothes has the advantages that the 5 percent thermal weight loss temperature (T5 percent) of the flame-retardant polyester fiber for clothes is 425-432 ℃, and the maximum decomposition temperature (T5 percent)_dm) 467-488 ℃;

the limit oxygen index of the flame-retardant polyester fiber is more than 30 percent, the flame-retardant time is not needed, and the number of the molten drops in 15s is 0.

The performance indexes of the flame-retardant polyester fiber for clothes are as follows: the fineness is 75-100 dtex, the breaking strength is more than or equal to 3.5cN/dtex, the elongation at break is 35.0 +/-3.0%, the deviation rate of linear density is less than or equal to 0.7%, the CV value of the breaking strength is less than or equal to 6.0%, the CV value of the elongation at break is less than or equal to 10.0%, the CV value of yarn evenness unevenness is less than or equal to 2.00%, the boiling water shrinkage is 7.5 +/-0.5%, and the oil content is 0.90 +/-0.20%.

The invention also provides a preparation method of the clothing flame-retardant polyester fiber, which is characterized in that the clothing flame-retardant polyester fiber is obtained by winding a spinning coil after the modified polyester is tackified by solid phase polycondensation;

the preparation method of the modified polyester comprises the following steps: uniformly mixing terephthalic acid, ethylene glycol, 2, 6-pyridinedicarboxylic acid, flame retardant 2-hydroxyethyl phenylphosphinic acid and zinc chloride, and then carrying out esterification reaction and polycondensation reaction in sequence to obtain the modified polyester.

The invention carries out coordination by adding zinc chloride during polymerization because the metal-ligand interaction can realize the memory characteristic of thermal responsiveness by reversible covalent crosslinking in the form of metal-ligand coordination bonds while keeping the dynamic reversibility of supramolecular bonds, namely the property that crosslinking nodes among molecular chain segments can be dissociated at a certain temperature and crosslinked network nodes are regenerated in the cooling process of the polyester. In the chips, 2, 6-pyridinedicarboxylic acid and zinc ion are coordinated, but the coordination can be dissociated by heating the screw, and the fibers can be reformed.

As a preferred technical scheme:

the preparation method of the flame-retardant polyester fiber for the clothes comprises the following steps of:

(1) performing esterification reaction;

preparing terephthalic acid, ethylene glycol, 2, 6-pyridinedicarboxylic acid and flame retardant 2-hydroxyethyl phenyl hypophosphorous acid into slurry, adding a catalyst, a stabilizer and zinc chloride, uniformly mixing, pressurizing in a nitrogen atmosphere to perform esterification reaction, wherein the pressurizing pressure is normal pressure to 0.3MPa, the temperature of the esterification reaction is 250-260 ℃, and the termination condition of the esterification reaction is as follows: the distilled water amount in the esterification reaction reaches more than 90 percent of a theoretical value;

(2) performing polycondensation reaction;

after the esterification reaction is finished, starting the polycondensation reaction in a low vacuum stage under the condition of negative pressure, stably pumping the pressure in the low vacuum stage from normal pressure to below 500Pa in 30-50 min at the reaction temperature of 250-260 ℃ for 30-50 min, then continuously pumping the vacuum to perform the polycondensation reaction in a high vacuum stage, further reducing the reaction pressure to below 100Pa, controlling the reaction temperature of 270-282 ℃ and the reaction time of 50-90 min, and obtaining the modified polyester.

The preparation method of the flame-retardant polyester fiber for the clothes has the advantage that the number average molecular weight of the modified polyester is 20000-25000.

According to the preparation method of the flame-retardant polyester fiber for the clothes, the molar ratio of the terephthalic acid, the ethylene glycol, the 2, 6-pyridinedicarboxylic acid and the flame retardant 2-hydroxyethyl phenylphosphinic acid is 1: 1.2-2.0: 0.06-0.08: 0.03-0.05, and the addition amounts of the catalyst and the stabilizer are respectively 0.01-0.05 wt% and 0.01-0.05 wt% of the addition amount of the terephthalic acid; the adding amount of the zinc chloride is 0.9-1.5 mol% of the adding amount of the terephthalic acid.

According to the preparation method of the flame-retardant polyester fiber for clothes, the catalyst is antimony trioxide, ethylene glycol antimony or antimony acetate, and the stabilizer is triphenyl phosphate, trimethyl phosphate or trimethyl phosphite.

The preparation method of the flame-retardant polyester fiber for clothing comprises the following spinning process parameters:

spinning temperature: 280-290 ℃;

cooling temperature: 20-25 ℃;

network pressure: 0.20 to 0.30 MPa;

a roll speed: 2200-2600 m/min;

first roll temperature: 75-85 ℃;

two roll speed: 3600-3900 m/min;

temperature of the two rolls: 135-165 ℃;

winding speed: 3550-3840 m/min.

The mechanism of the invention is as follows:

melt dripping is a characteristic that is common to almost all thermoplastic polymers. Many thermoplastic polymer materials including polyester are acted by high temperature, before the flammable substances are generated through degradation, the temperature is firstly close to the melting point of the polymer, at the moment, the polymer materials can be softened, shrunk and melted to generate molten drops, if the temperature of the polymer materials is continuously increased through external energy at the moment, the materials can be degraded, the viscosity of the polyester is greatly reduced through degradation, the generation of the molten drops is accelerated, the flammable volatile substances are promoted to be in a gas phase, and therefore the combustion phenomenon is generated. The heat generated by combustion is fed back to the ignition front of the polymer, promoting substance degradation, creating a benign cycle for the combustion process until the entire material is burned off.

Increasing the thermal degradation temperature of polyester is an effective way to reduce the number of droplets.

There are two possible ways of thermal degradation, one is cleavage between the macromolecular chains, generating terminal carboxyl groups and vinyl esters, and leading to a decrease in the relative molecular mass, at which point no loss in sample mass is observed; the other is degradation of the end of the macromolecule chain, which leads to the formation of carboxyl groups at the chain end and the release of gases such as acetaldehyde, and a reduction in the quality of the sample is observed. Both thermal degradation modes may also occur simultaneously.

The physical crosslinking points are increased, so that the activation energy of the thermal degradation reaction between chains can be effectively improved.

According to the invention, zinc and 2, 6-pyridinedicarboxylic acid form a chelate with two five-membered ring structures, so that on one hand, a molecular chain is stable, on the other hand, a physical crosslinking point is formed between two macromolecular chains, the stability of the molecular chain is further improved, the activation energy of the polyester inter-chain thermal degradation reaction is increased, the polyester thermal degradation temperature is further improved, and the melting dripping is effectively reduced.

Has the advantages that:

(1) according to the preparation method of the flame-retardant polyester fiber, Zn (II) and 2, 6-pyridinedicarboxylic acid are coordinated, physical crosslinking points are increased, and the activation energy of the interchain thermal degradation reaction can be effectively improved, so that the thermal degradation temperature of polyester is increased;

(2) the invention improves the thermal degradation temperature of the polyester through coordination, thereby achieving the purpose of effectively reducing molten drops.

Detailed Description

The invention will be further illustrated with reference to specific embodiments. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and such equivalents may fall within the scope of the present invention as defined in the appended claims.

Example 1

A preparation method of a flame-retardant polyester fiber for clothes comprises the following specific steps:

(1) preparation of modified polyester:

(1.1) esterification reaction;

preparing terephthalic acid, ethylene glycol, 2, 6-pyridinedicarboxylic acid and flame retardant 2-hydroxyethyl phenylphosphinic acid into slurry with the molar ratio of 1:1.2:0.06:0.03, adding a catalyst (antimony trioxide), a stabilizer (triphenyl phosphate) and zinc chloride, and uniformly mixing, wherein the adding amounts of the catalyst and the stabilizer are 0.02 wt% and 0.01 wt% of the adding amount of the terephthalic acid respectively, and the adding amount of the zinc chloride is 0.9 mol% of the adding amount of the terephthalic acid; then pressurizing in a nitrogen atmosphere to perform esterification reaction, wherein the pressurizing pressure is 0.2MPa, the temperature of the esterification reaction is 252 ℃, and the termination conditions of the esterification reaction are as follows: the distilled water amount in the esterification reaction reaches 95 percent of a theoretical value;

(1.2) polycondensation reaction;

after the esterification reaction is finished, starting the polycondensation reaction in a low vacuum stage under the negative pressure condition, smoothly pumping the pressure in the stage from normal pressure to the absolute pressure of 500Pa within 30min, controlling the reaction temperature to 254 ℃, controlling the reaction time to 40min, then continuing to pump vacuum, and carrying out the polycondensation reaction in a high vacuum stage, so that the reaction pressure is further reduced to the absolute pressure of 100Pa, the reaction temperature is 276 ℃, and the reaction time is 70min, thus preparing the modified polyester with the number average molecular weight of 20000;

(2) performing solid phase polycondensation tackifying on the modified polyester, and then spinning and winding to obtain the flame-retardant polyester fiber;

the spinning process parameters are as follows:

spinning temperature: 280 ℃;

cooling temperature: 20 ℃;

network pressure: 0.2 MPa;

a roll speed: 2200 m/min;

first roll temperature: 75 ℃;

two roll speed: 3600 m/min;

temperature of the two rolls: 135 deg.C;

winding speed: 3550 m/min.

The prepared polyester chain segment for the flame-retardant polyester fiber comprises a phthalic acid chain segment, an ethylene glycol chain segment, a flame retardant 2-hydroxyethyl phenylphosphinic acid chain segment and a 2, 6-pyridinedicarboxylic acid chain segment; the molar ratio of the terephthalic acid chain segment, the 2, 6-pyridinedicarboxylic acid chain segment and the flame retardant 2-hydroxyethyl phenylphosphinic acid chain segment is 1:0.06: 0.03; zn is arranged between 2, 6-pyridine dicarboxylic acid chain segments of different polyester chain segments²⁺Coordinated, 2, 6-pyridine dicarboxylic acid chain segment is coordinated with O atom on carbonyl and N atom on pyridine, and the coordination structure formed by coordination is as follows:

the 5 percent thermal weight loss temperature (T5 percent) of the flame-retardant polyester fiber is 425 ℃ when the flame-retardant polyester fiber is taken, and the maximum decomposition temperature (T5 percent)_dm) 468 ℃ is adopted; the limiting oxygen index of the flame-retardant polyester fiber is 30.1 percent, the afterflame time is not available, and the number of molten drops in 15s is 0; the performance indexes of the clothing flame-retardant polyester fiber are as follows: the fineness was 75dtex, the breaking strength was 3.5cN/dtex, the elongation at break was 38%, the linear density variation rate was 0.65%, the breaking strength CV value was 5.4%, the elongation at break CV value was 9%, the yarn evenness CV value was 1.8%, the boiling water shrinkage was 8%, and the oil content was 0.7%.

Example 2

A preparation method of a flame-retardant polyester fiber for clothes comprises the following specific steps:

(1) preparation of modified polyester:

(1.1) esterification reaction;

preparing terephthalic acid, ethylene glycol, 2, 6-pyridinedicarboxylic acid and flame retardant 2-hydroxyethyl phenylphosphinic acid into slurry with the molar ratio of 1:1.2:0.07:0.03, adding a catalyst (antimony trioxide), a stabilizer (triphenyl phosphate) and zinc chloride, and uniformly mixing, wherein the adding amounts of the catalyst and the stabilizer are 0.01 wt% and 0.02 wt% of the adding amount of the terephthalic acid respectively, and the adding amount of the zinc chloride is 1 mol% of the adding amount of the terephthalic acid; then pressurizing in a nitrogen atmosphere to perform esterification reaction, wherein the pressurizing pressure is 0.1MPa, the temperature of the esterification reaction is 250 ℃, and the termination conditions of the esterification reaction are as follows: the distilled water amount in the esterification reaction reaches 90 percent of the theoretical value;

(1.2) polycondensation reaction;

after the esterification reaction is finished, starting the polycondensation reaction in a low vacuum stage under the negative pressure condition, stably pumping the pressure in the stage from normal pressure to absolute pressure of 480Pa within 32min, controlling the reaction temperature to be 252 ℃ and the reaction time to be 45min, then continuing to pump vacuum, and carrying out the polycondensation reaction in a high vacuum stage to further reduce the reaction pressure to absolute pressure of 30Pa, control the reaction temperature to be 272 ℃ and control the reaction time to be 80min, thus obtaining the modified polyester with the number average molecular weight of 21000;

(2) performing solid phase polycondensation tackifying on the modified polyester, and then spinning and winding to obtain the flame-retardant polyester fiber;

the spinning process parameters are as follows:

spinning temperature: 282 ℃;

cooling temperature: 21 ℃;

network pressure: 0.2 MPa;

a roll speed: 2300 m/min;

first roll temperature: 77 ℃;

two roll speed: 3650 m/min;

temperature of the two rolls: 140 ℃;

winding speed: 3600 m/min.

The prepared polyester chain segment for the flame-retardant polyester fiber comprises a phthalic acid chain segment, an ethylene glycol chain segment, a flame retardant 2-hydroxyethyl phenylphosphinic acid chain segment and a 2, 6-pyridinedicarboxylic acid chain segment; the molar ratio of the terephthalic acid chain segment, the 2, 6-pyridinedicarboxylic acid chain segment and the flame retardant 2-hydroxyethyl phenylphosphinic acid chain segment is 1:0.07: 0.03; zn is arranged between 2, 6-pyridine dicarboxylic acid chain segments of different polyester chain segments²⁺Coordinated, 2, 6-pyridine dicarboxylic acid chain segment is coordinated with O atom on carbonyl and N atom on pyridine, and the coordination structure formed by coordination is as follows:

the 5 percent thermal weight loss temperature (T5 percent) of the flame-retardant polyester fiber is 426 ℃ when the flame-retardant polyester fiber is taken, and the maximum decomposition temperature (T5 percent)_dm) Is 470 ℃; the limiting oxygen index of the flame-retardant polyester fiber is 31 percent, the afterflame time is not needed, and the number of molten drops in 15s is 0; the performance indexes of the clothing flame-retardant polyester fiber are as follows: the fineness was 80dtex, the breaking strength was 3.6cN/dtex, the elongation at break was 37.6%, the linear density variation rate was 0.64%, the CV value of the breaking strength was 5.5%, the CV value of the elongation at break was 9.1%, the CV value of the yarn evenness unevenness was 1.8%, the shrinkage in boiling water was 7.7%, and the oil content was 0.9%.

Example 3

A preparation method of a flame-retardant polyester fiber for clothes comprises the following specific steps:

(1) preparation of modified polyester:

(1.1) esterification reaction;

preparing terephthalic acid, ethylene glycol, 2, 6-pyridinedicarboxylic acid and flame retardant 2-hydroxyethyl phenylphosphinic acid into slurry with the molar ratio of 1:1.2:0.08:0.03, adding a catalyst (antimony trioxide), a stabilizer (trimethyl phosphate) and zinc chloride, and uniformly mixing, wherein the adding amounts of the catalyst and the stabilizer are 0.03 wt% and 0.02 wt% of the adding amount of the terephthalic acid respectively, and the adding amount of the zinc chloride is 1.1 mol% of the adding amount of the terephthalic acid; then pressurizing in a nitrogen atmosphere to carry out esterification reaction, wherein the pressurizing pressure is 0.2MPa, the temperature of the esterification reaction is 254 ℃, and the termination conditions of the esterification reaction are as follows: the distilled water amount in the esterification reaction reaches 95 percent of a theoretical value;

(1.2) polycondensation reaction;

after the esterification reaction is finished, starting the polycondensation reaction in a low vacuum stage under the negative pressure condition, smoothly pumping the pressure in the stage from normal pressure to absolute pressure of 440Pa within 34min, controlling the reaction temperature to be 250 ℃ and the reaction time to be 50min, then continuing to pump vacuum, and carrying out the polycondensation reaction in a high vacuum stage to further reduce the reaction pressure to absolute pressure of 20Pa, control the reaction temperature to be 274 ℃ and control the reaction time to be 75min, thus preparing the modified polyester with the number average molecular weight of 22000;

(2) performing solid phase polycondensation tackifying on the modified polyester, and then spinning and winding to obtain the flame-retardant polyester fiber;

the spinning process parameters are as follows:

spinning temperature: 284 ℃;

cooling temperature: 21 ℃;

network pressure: 0.2 MPa;

a roll speed: 2400 m/min;

first roll temperature: 78 ℃;

two roll speed: 3700 m/min;

temperature of the two rolls: 145 ℃;

winding speed: 3650 m/min.

The prepared polyester chain segment for the flame-retardant polyester fiber comprises a phthalic acid chain segment, an ethylene glycol chain segment, a flame retardant 2-hydroxyethyl phenylphosphinic acid chain segment and a 2, 6-pyridinedicarboxylic acid chain segment; the molar ratio of the terephthalic acid chain segment, the 2, 6-pyridinedicarboxylic acid chain segment and the flame retardant 2-hydroxyethyl phenylphosphinic acid chain segment is 1:0.08: 0.03; zn is arranged between 2, 6-pyridine dicarboxylic acid chain segments of different polyester chain segments²⁺Coordinated, 2, 6-pyridine dicarboxylic acid chain segment is coordinated with O atom on carbonyl and N atom on pyridine, and the coordination structure formed by coordination is as follows:

the 5 percent thermal weight loss temperature (T5 percent) of the flame-retardant polyester fiber is 427 ℃ when the flame-retardant polyester fiber is taken, and the maximum decomposition temperature (T5 percent)_dm) 467 deg.C; the limit oxygen index of the flame-retardant polyester fiber is 30.5 percent, the afterflame time is not available, and the number of molten drops in 15s is 0; the performance indexes of the clothing flame-retardant polyester fiber are as follows: the fineness was 85dtex, the breaking strength was 3.5cN/dtex, the elongation at break was 37.1%, the linear density variation rate was 0.63%, the CV value of the breaking strength was 5.6%, the CV value of the elongation at break was 9.1%, the CV value of the yarn evenness unevenness was 1.9%, the shrinkage in boiling water was 7.8%, and the oil content was 0.8%.

Example 4

A preparation method of a flame-retardant polyester fiber for clothes comprises the following specific steps:

(1) preparation of modified polyester:

(1.1) esterification reaction;

preparing terephthalic acid, ethylene glycol, 2, 6-pyridinedicarboxylic acid and flame retardant 2-hydroxyethyl phenylphosphinic acid into slurry with the molar ratio of 1:1.2:0.06:0.04, adding a catalyst (ethylene glycol antimony), a stabilizer (trimethyl phosphate) and zinc chloride, and uniformly mixing, wherein the adding amounts of the catalyst and the stabilizer are 0.02 wt% and 0.03 wt% of the adding amount of the terephthalic acid respectively, and the adding amount of the zinc chloride is 1.2 mol% of the adding amount of the terephthalic acid; then pressurizing in a nitrogen atmosphere to perform esterification reaction, wherein the pressurizing pressure is 0.2MPa, the temperature of the esterification reaction is 256 ℃, and the termination conditions of the esterification reaction are as follows: the distilled water amount in the esterification reaction reaches 96 percent of a theoretical value;

(1.2) polycondensation reaction;

after the esterification reaction is finished, starting the polycondensation reaction in a low vacuum stage under the negative pressure condition, wherein the pressure in the stage is stably pumped from normal pressure to absolute pressure of 420Pa within 36min, the reaction temperature is 256 ℃, the reaction time is 35min, then continuing to pump vacuum, and carrying out the polycondensation reaction in a high vacuum stage, so that the reaction pressure is further reduced to absolute pressure of 19Pa, the reaction temperature is 270 ℃, and the reaction time is 90min, thus preparing the modified polyester with the number average molecular weight of 23000;

(2) performing solid phase polycondensation tackifying on the modified polyester, and then spinning and winding to obtain the flame-retardant polyester fiber;

the spinning process parameters are as follows:

spinning temperature: 285 ℃;

cooling temperature: 22 ℃;

network pressure: 0.3 MPa;

a roll speed: 2450 m/min;

first roll temperature: 79 ℃;

two roll speed: 3750 m/min;

temperature of the two rolls: 150 ℃;

winding speed: 3700 m/min.

The prepared polyester chain segment for the flame-retardant polyester fiber comprises a phthalic acid chain segment, an ethylene glycol chain segment, a flame retardant 2-hydroxyethyl phenylphosphinic acid chain segment and a 2, 6-pyridinedicarboxylic acid chain segment; terephthalic acid chain segment, 2, 6-pyridine dicarboxylic acid chain segment and flame retardant 2-hydroxyethylThe molar ratio of phenyl hypophosphorous acid chain segments is 1:0.06: 0.04; zn is arranged between 2, 6-pyridine dicarboxylic acid chain segments of different polyester chain segments²⁺Coordinated, 2, 6-pyridine dicarboxylic acid chain segment is coordinated with O atom on carbonyl and N atom on pyridine, and the coordination structure formed by coordination is as follows:

the 5 percent thermal weight loss temperature (T5 percent) of the flame-retardant polyester fiber is 428 ℃ when the flame-retardant polyester fiber is taken, and the maximum decomposition temperature (T5 percent)_dm) 477 ℃ is adopted; the limit oxygen index of the flame-retardant polyester fiber is 32 percent, the afterflame time is not needed, and the number of molten drops in 15s is 0; the performance indexes of the clothing flame-retardant polyester fiber are as follows: the fineness was 90dtex, the breaking strength was 3.6cN/dtex, the elongation at break was 36.9%, the linear density variation rate was 0.67%, the CV value of the breaking strength was 5.9%, the CV value of the elongation at break was 9.3%, the CV value of the yarn evenness unevenness was 1.9%, the shrinkage in boiling water was 7.5%, and the oil content was 0.9%.

Example 5

A preparation method of a flame-retardant polyester fiber for clothes comprises the following specific steps:

(1) preparation of modified polyester:

(1.1) esterification reaction;

preparing terephthalic acid, ethylene glycol, 2, 6-pyridinedicarboxylic acid and flame retardant 2-hydroxyethyl phenylphosphinic acid into slurry with the molar ratio of 1:1.2:0.07:0.04, adding a catalyst (ethylene glycol antimony), a stabilizer (trimethyl phosphite) and zinc chloride, and uniformly mixing, wherein the adding amounts of the catalyst and the stabilizer are 0.05 wt% and 0.04 wt% of the adding amount of the terephthalic acid respectively, and the adding amount of the zinc chloride is 1.3 mol% of the adding amount of the terephthalic acid; then pressurizing in a nitrogen atmosphere to carry out esterification reaction, wherein the pressurizing pressure is 0.3MPa, the temperature of the esterification reaction is 258 ℃, and the termination conditions of the esterification reaction are as follows: the distilled water amount in the esterification reaction reaches 96 percent of a theoretical value;

(1.2) polycondensation reaction;

after the esterification reaction is finished, starting the polycondensation reaction in the low vacuum stage under the negative pressure condition, stably pumping the pressure in the stage from normal pressure to absolute pressure of 400Pa within 38min, controlling the reaction temperature to 258 ℃, controlling the reaction time to be 33min, then continuing to pump vacuum, and carrying out the polycondensation reaction in the high vacuum stage, so that the reaction pressure is further reduced to absolute pressure of 18Pa, the reaction temperature is 278 ℃, and the reaction time is 65min, thus obtaining the modified polyester with the number average molecular weight of 24000;

(2) performing solid phase polycondensation tackifying on the modified polyester, and then spinning and winding to obtain the flame-retardant polyester fiber;

the spinning process parameters are as follows:

spinning temperature: 286 ℃;

cooling temperature: 23 ℃;

network pressure: 0.3 MPa;

a roll speed: 2500 m/min;

first roll temperature: 82 ℃;

two roll speed: 3800 m/min;

temperature of the two rolls: 155 ℃;

winding speed: 3800 m/min.

The prepared polyester chain segment for the flame-retardant polyester fiber comprises a phthalic acid chain segment, an ethylene glycol chain segment, a flame retardant 2-hydroxyethyl phenylphosphinic acid chain segment and a 2, 6-pyridinedicarboxylic acid chain segment; the molar ratio of the terephthalic acid chain segment, the 2, 6-pyridinedicarboxylic acid chain segment and the flame retardant 2-hydroxyethyl phenylphosphinic acid chain segment is 1:0.07: 0.04; zn is arranged between 2, 6-pyridine dicarboxylic acid chain segments of different polyester chain segments²⁺Coordinated, 2, 6-pyridine dicarboxylic acid chain segment is coordinated with O atom on carbonyl and N atom on pyridine, and the coordination structure formed by coordination is as follows:

the 5 percent thermal weight loss temperature (T5 percent) of the flame-retardant polyester fiber is 429 ℃, and the maximum decomposition temperature (T5 percent) of the flame-retardant polyester fiber is_dm) 473 deg.C; the limiting oxygen index of the flame-retardant polyester fiber is 31.6 percent, the afterflame time is not available, and the number of molten drops in 15s is 0; the performance indexes of the clothing flame-retardant polyester fiber are as follows: the fineness was 95dtex, the breaking strength was 3.7cN/dtex, the elongation at break was 36%, the linear density variation rate was 0.67%, the CV value of the breaking strength was 5.8%, the CV value of the elongation at break was 9.6%, and the CV value of the yarn evenness unevenness was 2%The boiling water shrinkage was 7.6% and the oil content was 1%.

Example 6

A preparation method of a flame-retardant polyester fiber for clothes comprises the following specific steps:

(1) preparation of modified polyester:

(1.1) esterification reaction;

preparing terephthalic acid, ethylene glycol, 2, 6-pyridinedicarboxylic acid and flame retardant 2-hydroxyethyl phenylphosphinic acid into slurry with the molar ratio of 1:1.2:0.08:0.05, adding a catalyst (antimony acetate), a stabilizer (trimethyl phosphite) and zinc chloride, and uniformly mixing, wherein the adding amounts of the catalyst and the stabilizer are 0.04 wt% and 0.05 wt% of the adding amount of the terephthalic acid respectively, and the adding amount of the zinc chloride is 1.4 mol% of the adding amount of the terephthalic acid; then pressurizing in a nitrogen atmosphere to perform esterification reaction, wherein the pressurizing pressure is 0.3MPa, the temperature of the esterification reaction is 260 ℃, and the termination conditions of the esterification reaction are as follows: the distilled water amount in the esterification reaction reaches 97 percent of the theoretical value;

(1.2) polycondensation reaction;

after the esterification reaction is finished, starting the polycondensation reaction in a low vacuum stage under the negative pressure condition, stably pumping the pressure in the stage from normal pressure to absolute pressure of 380Pa within 45min, controlling the reaction temperature to 259 ℃ and the reaction time to 32min, then continuing to pump vacuum, and carrying out the polycondensation reaction in a high vacuum stage to further reduce the reaction pressure to absolute pressure of 17Pa, control the reaction temperature to 280 ℃ and control the reaction time to 60min, thus obtaining the modified polyester with the number average molecular weight of 2450;

(2) performing solid phase polycondensation tackifying on the modified polyester, and then spinning and winding to obtain the flame-retardant polyester fiber;

the spinning process parameters are as follows:

spinning temperature: 288 ℃;

cooling temperature: 24 ℃;

network pressure: 0.3 MPa;

a roll speed: 2550 m/min;

first roll temperature: at 84 ℃;

two roll speed: 3850 m/min;

temperature of the two rolls: 160 ℃;

winding speed: 3820 m/min.

The prepared polyester chain segment for the flame-retardant polyester fiber comprises a phthalic acid chain segment, an ethylene glycol chain segment, a flame retardant 2-hydroxyethyl phenylphosphinic acid chain segment and a 2, 6-pyridinedicarboxylic acid chain segment; the molar ratio of the terephthalic acid chain segment, the 2, 6-pyridinedicarboxylic acid chain segment and the flame retardant 2-hydroxyethyl phenylphosphinic acid chain segment is 1:0.08: 0.05; zn is arranged between 2, 6-pyridine dicarboxylic acid chain segments of different polyester chain segments²⁺Coordinated, 2, 6-pyridine dicarboxylic acid chain segment is coordinated with O atom on carbonyl and N atom on pyridine, and the coordination structure formed by coordination is as follows:

the 5 percent thermal weight loss temperature (T5 percent) of the flame-retardant polyester fiber is 430 ℃ when the fabric is taken, and the maximum decomposition temperature (T5 percent)_dm) At 482 ℃; the limiting oxygen index of the flame-retardant polyester fiber is 32.5 percent, the afterflame time is not available, and the number of molten drops in 15s is 0; the performance indexes of the clothing flame-retardant polyester fiber are as follows: the fineness was 100dtex, the breaking strength was 3.7cN/dtex, the elongation at break was 35.7%, the linear density deviation ratio was 0.69%, the CV value of the breaking strength was 5.7%, the CV value of the elongation at break was 10%, the CV value of the yarn evenness degree was 2%, the shrinkage in boiling water was 7.4%, and the oil content was 1%.

Example 7

A preparation method of a flame-retardant polyester fiber for clothes comprises the following specific steps:

(1) preparation of modified polyester:

(1.1) esterification reaction;

preparing terephthalic acid, ethylene glycol, 2, 6-pyridinedicarboxylic acid and flame retardant 2-hydroxyethyl phenylphosphinic acid into slurry with the molar ratio of 1:1.2:0.08:0.05, adding a catalyst (antimony acetate), a stabilizer (trimethyl phosphite) and zinc chloride, and uniformly mixing, wherein the adding amounts of the catalyst and the stabilizer are 0.05 wt% and 0.05 wt% of the adding amount of the terephthalic acid respectively, and the adding amount of the zinc chloride is 1.5 mol% of the adding amount of the terephthalic acid; then pressurizing in a nitrogen atmosphere to perform esterification reaction, wherein the pressurizing pressure is 0.3MPa, the temperature of the esterification reaction is 260 ℃, and the termination conditions of the esterification reaction are as follows: the distilled water amount in the esterification reaction reaches 97 percent of the theoretical value;

(1.2) polycondensation reaction;

after the esterification reaction is finished, starting the polycondensation reaction in the low vacuum stage under the negative pressure condition, smoothly pumping the pressure in the stage from normal pressure to absolute pressure of 360Pa within 50min, controlling the reaction temperature to be 260 ℃ and the reaction time to be 30min, then continuing to pump vacuum, and carrying out the polycondensation reaction in the high vacuum stage to further reduce the reaction pressure to absolute pressure of 15Pa, control the reaction temperature to be 282 ℃ and control the reaction time to be 50min, thus obtaining the modified polyester with the number average molecular weight of 2500;

(2) performing solid phase polycondensation tackifying on the modified polyester, and then spinning and winding to obtain the flame-retardant polyester fiber;

the spinning process parameters are as follows:

spinning temperature: 290 ℃;

cooling temperature: 25 ℃;

network pressure: 0.3 MPa;

a roll speed: 2600 m/min;

first roll temperature: 85 ℃;

two roll speed: 3900 m/min;

temperature of the two rolls: 165 ℃;

winding speed: 3840 m/min.

The prepared polyester chain segment for the flame-retardant polyester fiber comprises a phthalic acid chain segment, an ethylene glycol chain segment, a flame retardant 2-hydroxyethyl phenylphosphinic acid chain segment and a 2, 6-pyridinedicarboxylic acid chain segment; the molar ratio of the terephthalic acid chain segment, the 2, 6-pyridinedicarboxylic acid chain segment and the flame retardant 2-hydroxyethyl phenylphosphinic acid chain segment is 1:0.08: 0.05; zn is arranged between 2, 6-pyridine dicarboxylic acid chain segments of different polyester chain segments²⁺Coordinated, 2, 6-pyridine dicarboxylic acid chain segment is coordinated with O atom on carbonyl and N atom on pyridine, and the coordination structure formed by coordination is as follows:

the 5 percent thermal weight loss temperature (T5 percent) of the flame-retardant polyester fiber is 432 ℃ when the flame-retardant polyester fiber is taken, and the maximum decomposition temperature (T5 percent)_dm) At 488 ℃; flame-retardant polyester fiber for clothesThe limiting oxygen index of the catalyst is 33 percent, the flame continuation time is not needed, and the number of molten drops in 15s is 0; the performance indexes of the clothing flame-retardant polyester fiber are as follows: the fineness was 100dtex, the breaking strength was 3.8cN/dtex, the elongation at break was 35%, the linear density deviation ratio was 0.7%, the breaking strength CV value was 6%, the elongation at break CV value was 9.8%, the yarn evenness CV value was 2%, the boiling water shrinkage was 7%, and the oil content was 1.1%.