CN111304781B

CN111304781B - Preparation method of moisture-absorbing and sweat-releasing ECDP fiber

Info

Publication number: CN111304781B
Application number: CN202010171408.0A
Authority: CN
Inventors: 董海良; 王晶晶; 刘园园; 胡超; 贾振宇; 王文; 徐锦龙
Original assignee: Zhejiang Hengyi Petrochemical Research Institute Co Ltd
Current assignee: Zhejiang Hengyi Petrochemical Research Institute Co Ltd
Priority date: 2020-03-12
Filing date: 2020-03-12
Publication date: 2022-05-24
Anticipated expiration: 2040-03-12
Also published as: CN111304781A

Abstract

The invention relates to the field of polyester polymerization and spinning, and discloses a preparation method of moisture absorption and sweat releasing ECDP fibers, which comprises the following steps: carrying out first esterification by taking terephthalic acid, ethylene glycol, a catalyst and an auxiliary agent as raw materials; using isophthalic acid-5-sulfonate and ethylene glycol as raw materials to perform pre-esterification; carrying out second esterification by taking a first esterification product, a pre-esterification product of m-phthalic acid-5-sulfonate, 2-methyl-1, 3-propanediol and a compound ether inhibitor as raw materials; taking the second esterification product and polyethylene glycol as raw materials, and carrying out pre-polycondensation; taking a pre-polycondensation product as a raw material, and carrying out final polycondensation; cooling and dicing the final polycondensation product to prepare slices; and drying, spinning and elasticizing the slices to obtain the finished product of the moisture-absorbing and sweat-releasing ECDP fiber. The preparation method of the invention can effectively improve the dyeing property and the moisture absorption and sweat releasing property of the polyester fiber, ensure the strength of the polyester fiber, and has stable and safe production.

Description

Preparation method of moisture-absorbing and sweat-releasing ECDP fiber

Technical Field

The invention relates to the field of polyester polymerization and spinning, in particular to a preparation method of moisture absorption and sweat releasing ECDP fibers.

Background

The polyester fiber is a synthetic fiber obtained by spinning polyester formed by polycondensation of organic dibasic acid and dihydric alcohol, is called PET fiber for short, and is commonly called terylene. The conventional polyester fiber has the advantages of high strength, high modulus, good elasticity and wear resistance, dimensional stability and the like due to the regularity of molecular chain segments and good crystallization performance, and is widely applied in the civil and industrial fields. However, polyester fibers lack functional groups capable of being combined with direct dyes, acid dyes, basic dyes and the like, and although polyester fibers have ester groups capable of forming hydrogen bonds with disperse dyes, dye molecules can enter the fibers only under the conditions of high temperature and high pressure due to high crystallinity and a compact structure, the dyeing process is high in energy consumption, large in pollution, limited by the disperse dyes, poor in dyeing vividness and poor in light fastness; in addition, the fibers have low moisture absorption, poor air permeability, and poor wearing comfort. In order to solve the two problems, researchers at home and abroad make a great deal of research and summarize that the modification methods of the fiber comprise the following steps: (1) polyester molecular structure modification such as cation modification and normal pressure dyeing cation modification; (2) the fiber structure is modified into a cross shape, a multi-blade shape, a triangular shape and other anisotropic cross sections.

The low-temperature cation dyeable polyester (ECDP) fiber is prepared by adding a third monomer and a fourth monomer to participate in copolymerization in the process of synthesizing the polyester fiber so as to realize normal-pressure low-temperature dyeability. The third monomer is sulfonate, and a sulfonic group of the third monomer is used as an anionic dye base and can be tightly combined with cationic dye through an ionic bond, so that the purpose of cationic dyeability is achieved. After the third monomer is introduced, although the dyeing of the copolyester has high color fastness, bright color and complete chromatogram, the strong polarity of the sulfonic acid group obviously improves the number of polar entanglement points of the copolyester compared with unmodified polyester, the steric hindrance effect of the sulfonic acid group limits the movement of a molecular chain, so that the rheological property of the modified polyester is poor, the copolyester is difficult to stir in the later polymerization stage and the spinning performance is poor, and the cationic dye dyeing of fibers still needs to be carried out under high pressure. Therefore, when the third monomer is introduced, a fourth monomer with a flexible chain segment is also introduced to improve the mobility of macromolecules in an amorphous region, so that the effect that the cationic dye can be dyed at normal pressure and low temperature is achieved.

The third monomer commonly used in the prior art is sodium bis-hydroxyethyl isophthalate-5-Sulfonate (SIPE), sodium dimethyl isophthalate-5-Sulfonate (SIPM), or a transesterification product thereof; the fourth monomer is polyethylene glycol or aromatic polyethylene glycol, etc. For example, chinese patent publication No. CN107129567B discloses a copolymerization type flame retardant ECDP polyester chip and a method for preparing the same, which uses terephthalic acid (PTA), Ethylene Glycol (EG), SIPM, polyethylene glycol (PEG), 2-carboxyethylphenylphosphinic acid (CEPPA) as main raw materials, and adopts a batch 4-pot process: and carrying out primary esterification, secondary esterification, pre-polycondensation and final polycondensation to obtain the copolymerized flame-retardant ECDP polyester chip. The first esterification raw material is PTA and EG to generate intermediate product BHET; the diester raw materials comprise BHET, a compound heat stabilizer, a compound ether inhibitor, a catalyst, PEG and pretreated SIPM; the pre-polycondensation raw material is a diester product and pretreated CEPPA; the final polycondensation raw material is a pre-polycondensation product. The SIPM pretreatment is to carry out ester exchange reaction on EG and SIPM to generate SIPE. The slice prepared by the preparation method has excellent hue, high melting point and excellent flame retardant property, and the fiber fabric prepared by the slice is dyed by cationic dye under normal pressure, so that the color is bright, the color fastness is excellent, and the difference of the dyeing color difference of products in different batches is small. However, there are the following problems: (1) a large amount of flammable and explosive liquid, namely methanol, can be generated in the SIPM pretreatment process, so that the production safety is influenced; (2) no research is made on the improvement of the moisture absorption and sweat releasing capacity of the fiber; (3) the introduction of PEG destroys the regularity and crystallinity of the segment, so that the dye can enter the molecular chain of the fiber, and the fiber strength is reduced.

Disclosure of Invention

In order to solve the technical problem, the invention provides a preparation method of the moisture absorption and sweat releasing ECDP fiber. The preparation method can effectively improve the dyeing property and the moisture absorption and sweat releasing property of the polyester fiber, ensures the strength of the polyester fiber, and has stable and safe production.

The specific technical scheme of the invention is as follows:

a preparation method of moisture absorption and sweat releasing ECDP fibers comprises the following steps:

(1) first esterification: mixing terephthalic acid, ethylene glycol, a catalyst and an auxiliary agent, pulping and uniformly stirring, and conveying the obtained slurry to a first esterification kettle for first esterification;

(2) pre-esterification of 5-sulfoisophthalic acid: adding m-phthalic acid-5-sulfonate and ethylene glycol into a pre-esterification kettle for pre-esterification;

(3) second esterification: adding a first esterification product, an m-phthalic acid-5-sulfonate pre-esterification product, 2-methyl-1, 3-propylene glycol and a compound ether inhibitor into a second esterification kettle to carry out second esterification;

(4) pre-polycondensation: adding a second esterification product and polyethylene glycol into a pre-polycondensation kettle for pre-polycondensation;

(5) final polycondensation: conveying the pre-polycondensation product to a final polycondensation kettle for final polycondensation;

(6) preparing a section: cooling and dicing the final polycondensation product to prepare slices;

(7) Preparing a fiber finished product: and drying, spinning and elasticizing the slices to obtain the finished product of the moisture-absorbing and sweat-releasing ECDP fiber.

The invention ensures effective dye base group-sulfonic acid group by introducing the third monomer SIPA, which can be tightly combined with cationic dye by ionic bond, thereby realizing cationic dyeability. After the SIPA is pre-esterified into the SIPE, the SIPA is subjected to secondary esterification, so that the problem of SIPA self-polymerization can be effectively avoided, and the dyeing stability is ensured. Compared with the prior art using the SIPM as a third monomer, the SIPA pre-esterification process does not produce flammable and explosive gas methanol, and the production is more stable and safe; compared with the prior art directly taking SIPE as a third monomer, the SIPE prepared freshly is better in the polyester synthesis process because SIPE is an EG mixed solution per se and has poor stability, particularly a SIPE solution with high concentration is easy to crystallize, and SIPE performance directly influences the synthesis of polyester and influences the dye uptake and dyeing uniformity of finally prepared fibers.

According to the invention, the fourth monomer PEG with the flexible chain segment is introduced, so that the regularity of the chain segment is effectively destroyed, the flexibility of the molecular chain is improved, the rheological property and spinnability of the polyester are improved, and meanwhile, the amorphous region in the fiber can be further enlarged, so that the dye can easily enter the interior of the molecular chain of the fiber during fiber dyeing, the dye uptake is higher, and the coloring is more uniform. In addition, by reducing the crystallinity of the polyester, water molecules can enter the interior of a fiber molecular chain more easily, and the moisture absorption and sweat releasing performance of the fiber is improved.

On the basis, the fifth monomer 2-methyl-1, 3-propylene glycol (MPO) is introduced, the asymmetric structure of the MPO enables macromolecular chains of the copolyester to be looser, meanwhile, the existence of methyl branched chains can prevent polyester chains from being close to and overlapped, and the crystallization of the polyester is effectively inhibited, so that dye molecules can enter the interior of a fiber molecular chain more easily due to the introduction of the MPO, and the spinnability of the fiber can be improved; meanwhile, MPO contains hydrophilic group-OH, and water molecules can easily enter a fiber molecular chain by changing the crystallinity of polyester, so that the moisture absorption and sweat releasing performance of the fiber can be effectively improved. Therefore, the introduction of MPO can reduce the amount of PEG used to reduce the magnitude of the decrease in fiber strength.

Preferably, in the step (1), the molar ratio of the terephthalic acid to the ethylene glycol is 1: 1.1-1.5; and/or

In the step (2), the molar ratio of the isophthalic acid-5-sulfonate to the ethylene glycol is 1: 4-10; and/or

In the step (3), the addition amounts of the m-phthalic acid-5-sulfonate pre-esterification product and the 2-methyl-1, 3-propanediol are respectively 0.3-10 wt% and 0.5-30 wt% of the first esterification product.

Preferably, in the step (1), the catalyst is at least one of antimony trioxide, antimony acetate and ethylene glycol antimony, and the molar ratio of the terephthalic acid to the catalyst is 1: 0.0002-0.0004; and/or

In the step (1), the auxiliary agent is at least one of trimethyl phosphate, triethyl phosphate, tripropyl phosphate and triphenyl phosphate, and the molar ratio of terephthalic acid to the auxiliary agent is 1: 0.00005-0.0001; and/or

In the step (3), the compound ether inhibitor is at least two of sodium acetate, disodium hydrogen phosphate, sodium dihydrogen phosphate, dipotassium hydrogen phosphate, potassium dihydrogen phosphate and phosphoric acid, and the addition amount of the compound ether inhibitor is 0.1-1 wt% of the first esterification product; and/or in the step (4), the molecular weight of the polyethylene glycol is 1000-10000, and the addition amount of the polyethylene glycol is 0.5-30 wt% of the first esterification product.

Preferably, in the step (1), the first esterification is carried out at 230-255 ℃ and 40-60 kPa, and the esterification rate is controlled to be more than 80%; and/or

In the step (2), pre-esterification is carried out at 120-180 ℃ for 2-5 h, the reaction end point is determined when the receiving amount of effluent reaches a theoretical value, and the reaction temperature in the whole reaction process does not exceed 180 ℃; and/or

In the step (3), the second esterification is carried out at 235-260 ℃ and 10-30 kPa, and the esterification rate is controlled to be more than 93%; and/or

In the step (4), the pre-polycondensation is carried out at 260-285 ℃ and 10-30 kPa for 1-2 h; and/or

In the step (5), final polycondensation is carried out at 260-285 ℃ and 100-200 Pa for 1.5-3 h.

Preferably, in the step (4), polyethylene glycol is added into the prepolycondensation kettle through a pipeline.

The fourth monomer PEG is added in the pre-shrinking pipeline, so that the retention time of the fourth monomer can be reduced, the degradation of the fourth monomer can be reduced, and the stability of the superfine denier spinning is ensured.

Preferably, in the step (6), the final polycondensation product and the polypropylene are prepared into blended slices, and the specific steps are as follows: and fully mixing the final polycondensation product with polypropylene according to the mass ratio of 1: 0.02-0.05, then carrying out melt blending granulation by using a double-screw extruder, cooling and pelletizing.

The copolyester prepared by the first esterification, the second esterification, the pre-polycondensation and the final polycondensation is polar, has poor compatibility with non-polar polypropylene, can generate phase separation during spinning forming to form a plurality of crack pores, increases the accessible area of dye molecules, and ensures that the dye molecules are easier to diffuse into fibers, thereby improving the dyeing property of the fibers, and also ensuring that water molecules are easier to enter the fibers, thereby improving the moisture absorption and sweat releasing properties of the fibers. At the same time, however, the phase separation causes a decrease in the fiber strength, and therefore, the amount of polypropylene to be added must not be controlled to be excessively large.

Preferably, in the step (6), the polypropylene is modified polypropylene, and the preparation process is as follows:

1) preparation of modified hydroxyethyl sulfate: dispersing vinyl sulfate into alcohol, adding a ring-opening catalyst, uniformly mixing, heating to 70-80 ℃, continuously dropwise adding glycidyl methacrylate at the temperature, continuously stirring until the reaction is finished, then recovering the ring-opening catalyst, and removing the alcohol and excessive glycidyl methacrylate by reduced pressure rotary evaporation;

2) preparing modified polypropylene: mixing propylene and modified hydroxyethyl sulfate according to a molar ratio of 1: 0.001-0.003, and polymerizing for 1-2 h at 85-95 ℃ and 1.5-2.0 MPa.

The modified hydroxyethyl sulfate is a compound with carbon-carbon double bonds after the hydroxyethyl sulfate is modified. Because the sulfuric acid group can be tightly combined with the cationic dye through an ionic bond, the copolymerization product (modified polypropylene) of the polypropylene and the modified hydroxyethyl sulfate can be dyed by the cationic dye, so that the fiber prepared by blending and slicing can be dyed more uniformly. In addition, the polypropylene fiber can destroy the regularity of polypropylene through copolymerization with modified hydroxyethyl sulfate, so that dye molecules and water molecules can enter the molecular chain of the polypropylene more easily, and the dyeing property, the moisture absorption and the sweat releasing property of the fiber are enhanced. Meanwhile, the copolymerization with the modified hydroxyethyl sulfate can increase the polarity of the polypropylene, improve the compatibility of the polypropylene and the copolyester prepared by the invention and influence the exertion of the function of the polypropylene, so that the addition amount of the modified hydroxyethyl sulfate needs to be controlled not to be too large.

Hydroxyethyl sulfate provides an anionic dye base but is not copolymerizable with propylene and thus requires modification to attach a carbon-carbon double bond. The modification principle is that epoxy groups on glycidyl methacrylate and terminal hydroxyl groups on hydroxyethyl sulfate are subjected to ring-opening reaction under the action of a catalyst, so that the glycidyl methacrylate is connected to the hydroxyethyl sulfate, and the reaction formula is as follows: preferably, in the step (7), a trilobal spinneret is used for spinning during the spinning process.

The trilobal spinneret plate is adopted for spinning, so that the specific surface area of the fiber can be increased while the spinning strength is ensured, and the moisture absorption and sweat releasing performance is further optimized.

Preferably, in the step (7), the spinneret plate hole length of the trilobal spinneret plate is 0.3-1.6 mm, and the leaf width is 0.1-0.8 mm.

Preferably, in the step (7), the spinning temperature is 270-290 ℃, the speed is 1200-3000 m/min, and the air speed of air blowing cooling after spinning is 1.5-2.5 m/min; and/or

In the step (7), in the elasticizing process, the stretching speed is 600-900 m/min, the stretching multiple is 1.6-2.0, the speed ratio is 1.8-2.8, the temperature of the first heating box is 120-160 ℃, and the temperature of the second heating box is 120-160 ℃.

Compared with the prior art, the invention has the following advantages:

(1) compared with the prior art using SIPM or SIPE as the second monomer, the SIPA is used as the second monomer, the production is more stable and safer, and the prepared fiber has higher dye uptake and more uniform dyeing;

(2) on the basis of ensuring the fiber dyeing performance and the moisture absorption and sweat releasing performance, the consumption of PEG can be reduced by introducing a fifth monomer MPO, so that the reduction amplitude of the fiber strength is reduced;

(3) the trefoil spinneret plate is adopted for spinning, so that the moisture absorption and sweat releasing performance of the polyester fiber can be further improved;

(4) the polyester fiber can further improve the dyeing property and the moisture absorption and sweat releasing property of the polyester fiber by blending with the modified polypropylene.

Detailed Description

The present invention will be further described with reference to the following examples.

General examples

(1) first esterification: mixing terephthalic acid, ethylene glycol, a catalyst and an auxiliary agent, pulping and uniformly stirring, conveying the obtained slurry to a first esterification kettle for first esterification, reacting at 230-255 ℃ under 40-60 kPa, and controlling the esterification rate to be more than 80%; wherein the catalyst is at least one of antimony trioxide, antimony acetate and ethylene glycol antimony, and the auxiliary agent is at least one of trimethyl phosphate, triethyl phosphate, tripropyl phosphate and triphenyl phosphate; the molar ratio of the terephthalic acid to the ethylene glycol to the catalyst to the auxiliary agent is 1: 1.1-1.5: 0.0002-0.0004: 0.00005-0.0001;

(2) Pre-esterification of isophthalic acid-5-sulfonate: adding m-phthalic acid-5-sulfonate and ethylene glycol into a pre-esterification kettle, reacting for 2-5 h at 120-180 ℃, wherein the reaction end point is obtained when the receiving amount of effluent reaches a theoretical value, and the reaction temperature in the whole reaction process is not more than 180 ℃; wherein the molar ratio of the m-phthalic acid-5-sulfonate to the ethylene glycol is 1: 4-10;

(3) second esterification: adding a first esterification product, an m-phthalic acid-5-sulfonate pre-esterification product, 2-methyl-1, 3-propylene glycol and a compound ether inhibitor into a second esterification kettle, reacting at 235-260 ℃ under the pressure of 10-30 kPa, and controlling the esterification rate to be more than 93%; wherein the compound ether-proof agent is at least two of sodium acetate, disodium hydrogen phosphate, sodium dihydrogen phosphate, dipotassium hydrogen phosphate, potassium dihydrogen phosphate and phosphoric acid; the addition amounts of the isophthalic acid-5-sulfonate pre-esterification product, 2-methyl-1, 3-propylene glycol and the compound ether inhibitor are respectively 0.3-10 wt%, 0.5-30 wt% and 0.1-1 wt% of the first esterification product;

(4) pre-polycondensation: conveying the second esterification product to a pre-polycondensation kettle, adding polyethylene glycol into the pre-polycondensation kettle through a pipeline, and reacting for 1-2 hours at 260-285 ℃ under 10-30 kPa; wherein the molecular weight of the polyethylene glycol is 1000-10000; the addition amount of the polyethylene glycol is 0.5-30 wt% of the first esterification product.

(5) Final polycondensation: conveying the pre-polycondensation product to a final polycondensation kettle, and reacting for 1.5-3 h at 260-285 ℃ and 100-200 Pa;

(6) preparing a slice: cooling and dicing the final polycondensation product to prepare slices;

(7) preparing a fiber finished product: drying, spinning and elasticizing the slices to obtain a finished product of the moisture-absorbing and sweat-releasing ECDP fiber; wherein, the spinning process adopts a trilobal spinneret plate with the hole length of 0.3-1.6 mm and the leaf width of 0.1-0.8 mm to spray spinning, the spinning temperature is 270-290 ℃, the speed is 1200-3000 m/min, and the air speed of air blowing cooling after spinning is 1.5-2.5 m/min; in the elasticizing process, the stretching speed is 600-900 m/min, the stretching multiple is 1.6-2.0, the speed ratio is 1.8-2.8, the temperature of the first heating box is 120-160 ℃, and the temperature of the second heating box is 120-160 ℃.

Optionally, in the step (6), the final polycondensation product and polypropylene are prepared into blended slices, and the specific steps are as follows: and fully mixing the final polycondensation product with polypropylene according to the mass ratio of 1: 0.02-0.05, then carrying out melt blending granulation by using a double-screw extruder, cooling and pelletizing.

Optionally, the polypropylene is modified polypropylene, and the preparation process is as follows:

1) preparing modified hydroxyethyl sulfate: dispersing vinyl sulfate into alcohol, adding a ring-opening catalyst, uniformly mixing, heating to 70-80 ℃, continuously dropwise adding glycidyl methacrylate at the temperature, continuously stirring until the reaction is finished, then recovering the ring-opening catalyst, and removing the alcohol and excessive glycidyl methacrylate by reduced pressure rotary evaporation;

Example 1

(1) first esterification: mixing terephthalic acid, ethylene glycol antimony and triethyl phosphate, pulping and uniformly stirring, conveying the obtained slurry to a first esterification kettle for first esterification, reacting at 250 ℃ and 60kPa, and controlling the esterification rate to be more than 85%; wherein the molar ratio of the terephthalic acid to the ethylene glycol to the antimony ethylene glycol to the trimethyl phosphate is 1:1.1:0.0003: 0.0001;

(2) pre-esterification of 5-sodium m-phthalic acid sulfonate: adding 5-sodium sulfoisophthalate and ethylene glycol into a pre-esterification kettle, reacting for 3 hours at 180 ℃, wherein the reaction end point is obtained when the receiving amount of effluent reaches the theoretical value, and the reaction temperature in the whole reaction process is not more than 180 ℃; wherein the molar ratio of the isophthalic acid-5-sodium sulfonate to the ethylene glycol is 1: 6; after the reaction is finished, conveying the esterified liquid to an adjusting tank, and diluting SIPE to a concentration of 35%;

(3) second esterification: adding a first esterification product, a pre-esterification product of isophthalic acid-5-sodium sulfonate, 2-methyl-1, 3-propylene glycol and a compound ether inhibitor into a second esterification kettle, and reacting at 245 ℃ and under the pressure of 20kPa, wherein the esterification rate is controlled to be more than 93%; wherein the compound ether-proof agent is a mixture of sodium acetate and disodium hydrogen phosphate which are mixed according to the mass ratio of 1: 1; the addition amounts of the isophthalic acid-5-sodium sulfonate pre-esterification product, the 2-methyl-1, 3-propylene glycol and the compound ether inhibitor are respectively 6.5 wt%, 1 wt% and 0.15 wt% of the first esterification product;

(4) Pre-polycondensation: conveying the second esterification product to a pre-polycondensation kettle, adding polyethylene glycol with molecular weight of 2000 into the pre-polycondensation kettle through a pipeline, and reacting for 1.5h at 270 ℃ under 10 kPa; wherein the addition amount of the polyethylene glycol is 2 wt% of the first esterification product.

(5) Final polycondensation: conveying the pre-polycondensation product to a final polycondensation kettle, and reacting for 2h at 272 ℃ and 100 Pa;

(7) preparing a fiber finished product: drying the slices, and spinning by using a trilobal spinneret plate with the hole length of 1.0mm and the leaf width of 0.5mm at the spinning temperature of 280 ℃ and the speed of 2800m/min, wherein the air speed of air blowing cooling after spinning is 1.5 m/min; then winding to prepare pre-oriented yarn, wherein the strength of the pre-oriented yarn is 2.2 cN/dtex; the finished product of the moisture absorption and sweat releasing ECDP fiber is prepared by texturing the pre-oriented yarn, wherein in the texturing process, the drawing speed is 800m/min, the drawing multiple is 1.8, the speed ratio is 2.3, the temperature of a first heating box is 155 ℃, and the temperature of a second heating box is 145 ℃.

Example 2

(2) Pre-esterification of 5-sodium m-phthalic acid sulfonate: adding 5-sodium sulfoisophthalate and ethylene glycol into a pre-esterification kettle, reacting for 3 hours at 180 ℃, wherein the reaction end point is obtained when the receiving amount of effluent reaches the theoretical value, and the reaction temperature in the whole reaction process is not more than 180 ℃; wherein the mol ratio of the m-phthalic acid-5-sodium sulfonate to the glycol is 1: 6; after the reaction is finished, conveying the esterified liquid to an adjusting tank, and diluting SIPE to the concentration of 35%;

(3) second esterification: adding a first esterification product, a pre-esterification product of isophthalic acid-5-sodium sulfonate, 2-methyl-1, 3-propylene glycol and a compound ether inhibitor into a second esterification kettle, and reacting at 245 ℃ and under the pressure of 20kPa, wherein the esterification rate is controlled to be more than 93%; wherein the compound ether-proof agent is a mixture of sodium acetate and disodium hydrogen phosphate which are mixed according to the mass ratio of 1: 1; the addition amounts of the isophthalic acid-5-sodium sulfonate pre-esterification product, the 2-methyl-1, 3-propylene glycol and the compound ether inhibitor are respectively 6.5 wt%, 1.5 wt% and 0.15 wt% of the first esterification product;

(4) pre-polycondensation: conveying the second esterification product to a pre-polycondensation kettle, adding polyethylene glycol with molecular weight of 2000 into the pre-polycondensation kettle through a pipeline, and reacting for 1.5h at 270 ℃ under 10 kPa; wherein the addition amount of polyethylene glycol is 1.5 wt% of the first esterification product.

(7) preparing a fiber finished product: drying the slices, and spinning by using a trilobal spinneret plate with the hole length of 1.0mm and the leaf width of 0.5mm at the spinning temperature of 280 ℃ and the speed of 2800m/min, wherein the air speed of air blowing cooling after spinning is 1.5 m/min; then winding to obtain pre-oriented yarns, wherein the strength of the pre-oriented yarns is 2.2 cN/dtex; the finished product of the moisture absorption and sweat releasing ECDP fiber is prepared by texturing the pre-oriented yarn, wherein in the texturing process, the drawing speed is 800m/min, the drawing multiple is 1.8, the speed ratio is 2.3, the temperature of a first heating box is 155 ℃, and the temperature of a second heating box is 145 ℃.

Example 3

(3) second esterification: adding a first esterification product, a pre-esterification product of isophthalic acid-5-sodium sulfonate, 2-methyl-1, 3-propylene glycol and a compound ether inhibitor into a second esterification kettle, and reacting at 245 ℃ and under the pressure of 20kPa, wherein the esterification rate is controlled to be more than 93%; wherein the compound ether-proof agent is a mixture of sodium acetate and disodium hydrogen phosphate which are mixed according to the mass ratio of 1: 1; the addition amounts of the isophthalic acid-5-sodium sulfonate pre-esterification product, the 2-methyl-1, 3-propylene glycol and the compound ether inhibitor are respectively 7 wt%, 1.5 wt% and 0.15 wt% of the first esterification product;

(5) Final polycondensation: conveying the pre-polycondensation product to a final polycondensation kettle, and reacting for 2 hours at 272 ℃ and 100 Pa;

Example 4

(3) second esterification: adding a first esterification product, a pre-esterification product of isophthalic acid-5-sodium sulfonate, 2-methyl-1, 3-propylene glycol and a compound ether inhibitor into a second esterification kettle, and reacting at 245 ℃ and under the pressure of 20kPa, wherein the esterification rate is controlled to be more than 93%; wherein the compound ether-proof agent is a mixture of sodium acetate and disodium hydrogen phosphate which are mixed according to the mass ratio of 1: 1; the addition amounts of the isophthalic acid-5-sodium sulfonate pre-esterification product, the 2-methyl-1, 3-propylene glycol and the compound ether inhibitor are respectively 6.5 wt%, 2 wt% and 0.15 wt% of the first esterification product;

(4) pre-polycondensation: conveying the second esterification product to a pre-polycondensation kettle, adding polyethylene glycol with molecular weight of 2000 into the pre-polycondensation kettle through a pipeline, and reacting for 1.5h at 270 ℃ under 10 kPa; wherein the addition amount of the polyethylene glycol is 1 wt% of the first esterification product.

Example 5

(2) Pre-esterification of 5-sodium m-phthalic acid sulfonate: adding 5-sodium sulfoisophthalate and ethylene glycol into a pre-esterification kettle, reacting for 3 hours at 180 ℃, wherein the reaction end point is obtained when the receiving amount of effluent reaches a theoretical value, and the reaction temperature in the whole reaction process is not more than 180 ℃; wherein the mol ratio of the m-phthalic acid-5-sodium sulfonate to the glycol is 1: 6; after the reaction is finished, conveying the esterified liquid to an adjusting tank, and diluting SIPE to the concentration of 35%;

(6) preparing modified polypropylene:

(6.1) preparation of modified sodium hydroxyethyl sulfate: dispersing sodium vinyl sulfate into alcohol, adding a ring-opening catalyst, uniformly mixing, heating to 75 ℃, continuously dropwise adding glycidyl methacrylate at the temperature, continuously stirring until the reaction is finished, then recovering the ring-opening catalyst, removing the alcohol and excessive glycidyl methacrylate by reduced pressure rotary evaporation, and drying in vacuum to obtain modified hydroxyethyl sodium sulfate powder; wherein, the ring-opening catalyst is weak base resin loaded with tertiary amine functional group; the molar ratio of the ring-opening catalyst to the sodium vinyl sulfate is 1: 0.0003;

(6.2) preparation of modified Polypropylene: conveying modified hydroxyethyl sodium sulfate powder into a reaction kettle through nitrogen, conveying propylene into the reaction kettle, and polymerizing for 2 hours at 90 ℃ and 1.5 MPa; wherein the mol ratio of the propylene to the modified hydroxyethyl sodium sulfate is 1: 0.002;

(7) preparing a blending slice: fully mixing the final polycondensation product with modified polypropylene according to the mass ratio of 1:0.05, then carrying out melt blending granulation by using a double-screw extruder, cooling, and carrying out grain cutting to obtain blending slices;

(8) Preparing a fiber finished product: drying the blended slices, and spinning by using a trilobal spinneret plate with the hole length of 1.0mm and the leaf width of 0.5mm at the spinning temperature of 280 ℃ and the speed of 2800m/min, wherein the air speed of air blowing cooling after spinning is 1.5 m/min; then winding to obtain pre-oriented yarns, wherein the strength of the pre-oriented yarns is 2.2 cN/dtex; the finished product of the moisture absorption and sweat releasing ECDP fiber is prepared by texturing the pre-oriented yarn, wherein in the texturing process, the drawing speed is 800m/min, the drawing multiple is 1.8, the speed ratio is 2.3, the temperature of a first heating box is 155 ℃, and the temperature of a second heating box is 145 ℃.

Example 6

(6) preparing modified polypropylene:

(6.1) preparation of modified sodium hydroxyethyl sulfate: dispersing sodium vinyl sulfate into alcohol, adding a ring-opening catalyst, uniformly mixing, heating to 75 ℃, continuously dropwise adding glycidyl methacrylate at the temperature, continuously stirring until the reaction is finished, then recovering the ring-opening catalyst, and removing the alcohol and the excessive glycidyl methacrylate by reduced pressure rotary evaporation; wherein, the ring-opening catalyst is weak base resin loaded with tertiary amine functional group; the molar ratio of the ring-opening catalyst to the sodium vinyl sulfate is 1: 0.0003; (6.2) preparation of modified Polypropylene: dissolving modified hydroxyethyl sodium sulfate in alcohol, and polymerizing with propylene at 90 deg.C and 1.5MPa for 2 h; wherein the mol ratio of the propylene to the modified hydroxyethyl sodium sulfate is 1: 0.002;

(7) Preparing a blending slice: fully mixing the final polycondensation product with modified polypropylene according to the mass ratio of 1:0.02, then carrying out melt blending granulation by using a double-screw extruder, cooling, and carrying out grain cutting to obtain blending slices;

(8) preparing a fiber finished product: drying the blended slices, and spinning by using a trilobal spinneret plate with the hole length of 1.0mm and the leaf width of 0.5mm at the spinning temperature of 280 ℃ and the speed of 2800m/min, wherein the air speed of air blowing cooling after spinning is 1.5 m/min; then winding to prepare pre-oriented yarn, wherein the strength of the pre-oriented yarn is 2.2 cN/dtex; the finished product of the moisture absorption and sweat releasing ECDP fiber is prepared by texturing the pre-oriented yarn, wherein in the texturing process, the drawing speed is 800m/min, the drawing multiple is 1.8, the speed ratio is 2.3, the temperature of a first heating box is 155 ℃, and the temperature of a second heating box is 145 ℃.

Comparative example 1

(3) second esterification: adding a first esterification product, a pre-esterification product of isophthalic acid-5-sodium sulfonate, 2-methyl-1, 3-propylene glycol and a compound ether inhibitor into a second esterification kettle, and reacting at 245 ℃ and under the pressure of 20kPa, wherein the esterification rate is controlled to be more than 93%; wherein the compound ether-proof agent is a mixture of sodium acetate and disodium hydrogen phosphate which are mixed according to the mass ratio of 1: 1; the addition amounts of the isophthalic acid-5-sodium sulfonate pre-esterification product, the 2-methyl-1, 3-propylene glycol and the compound ether inhibitor are respectively 6.5 wt%, 0.2 wt% and 0.15 wt% of the first esterification product;

(4) pre-polycondensation: conveying the second esterification product to a pre-polycondensation kettle, adding polyethylene glycol with molecular weight of 2000 into the pre-polycondensation kettle through a pipeline, and reacting for 1.5h at 270 ℃ under 10 kPa; wherein the addition amount of polyethylene glycol is 3 wt% of the first esterification product.

Comparative example 2

(2) Pre-esterification of 5-sodium m-phthalic acid sulfonate: adding 5-sodium sulfoisophthalate and ethylene glycol into a pre-esterification kettle, reacting for 3 hours at 180 ℃, wherein the reaction end point is obtained when the receiving amount of effluent reaches the theoretical value, and the reaction temperature in the whole reaction process is not more than 180 ℃; wherein the mol ratio of the m-phthalic acid-5-sodium sulfonate to the glycol is 1: 6; after the reaction is finished, conveying the esterified liquid to an adjusting tank, and diluting SIPE to a concentration of 35%;

(3) second esterification: adding a first esterification product, a pre-esterification product of isophthalic acid-5-sodium sulfonate, 2-methyl-1, 3-propylene glycol and a compound ether inhibitor into a second esterification kettle, and reacting at 245 ℃ and under the pressure of 20kPa, wherein the esterification rate is controlled to be more than 93%; wherein the compound ether-proof agent is a mixture of sodium acetate and disodium hydrogen phosphate which are mixed according to the mass ratio of 1: 1; the addition amounts of the isophthalic acid-5-sodium sulfonate pre-esterification product, the 2-methyl-1, 3-propylene glycol and the compound ether inhibitor are respectively 6.5 wt%, 3 wt% and 0.15 wt% of the first esterification product;

(4) pre-polycondensation: conveying the second esterification product to a pre-polycondensation kettle, adding polyethylene glycol with molecular weight of 2000 into the pre-polycondensation kettle through a pipeline, and reacting for 1.5h at 270 ℃ under 10 kPa; wherein the addition amount of the polyethylene glycol is 0.2 wt% of the first esterification product.

The intrinsic viscosity, melting point, strength, moisture absorption and dyeing saturation values of the fibers obtained in examples 1 to 6 and comparative examples 1 to 2 were measured, and the results are shown in Table 1.

TABLE 1

In examples 1 to 4, the amounts of SIPE, MPO and PEG were varied within the range of the present invention, and the prepared fibers had no significant difference in viscosity, melting point, strength, hygroscopicity and dyeing saturation value, and the dyeing saturation value was all greater than 8, and the hygroscopicity was all greater than 0.8, indicating that the fibers prepared by the preparation method of the present invention have good dyeing properties and moisture absorption and sweat releasing properties.

Examples 5 and 6 blend chips were prepared from the final polycondensation product and the modified polypropylene, and blended fibers were prepared, all other experimental procedures being the same as in example 2. The results show that the moisture absorption and saturation dyeing values of the fibers obtained in examples 5 and 6 are significantly increased as compared to example 2, which indicates that the dyeing properties and moisture absorption and sweat releasing properties of the polyester fiber can be effectively improved by copolymerizing with the modified polypropylene.

The use amount of MPO is reduced in comparative example 1, and the total use amount of MPO and PEG is similar to that of examples 1-4, and the results show that the moisture absorption and dyeing saturation values of the fiber prepared in comparative example 1 are similar to those of examples 1-4, but the strength is obviously lower than those of examples 1-4. Therefore, the prior art only introducing the third monomer SIPE and the fourth monomer PEG obviously reduces the fiber strength by increasing the consumption of PEG to achieve the hygroscopicity and the dyeing saturation value similar to those of the invention; according to the invention, by introducing the fifth monomer MPO, the consumption of PEG can be reduced, so that the reduction amplitude of the fiber strength is reduced.

The use amount of PEG is reduced in comparative example 2, the total use amount of MPO and PEG is similar to that of examples 1-4, and the results show that the strength and dyeing saturation value of the fiber prepared in comparative example 2 are similar to those of examples 1-4, but the hygroscopicity is obviously lower than that of examples 1-4. It is understood that MPO cannot replace PEG, and that the use of PEG is not as small as possible, and that when it is less than the range of the present invention (0.5 to 30 wt%), the fiber strength is not increased, and the moisture absorption is largely affected.

The raw materials and equipment used in the invention are common raw materials and equipment in the field if not specified; the methods used in the present invention are conventional in the art unless otherwise specified.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and all simple modifications, alterations and equivalents of the above embodiments according to the technical spirit of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. A preparation method of moisture absorption and sweat releasing ECDP fiber is characterized by comprising the following steps:

(2) pre-esterification of isophthalic acid-5-sulfonate: adding m-phthalic acid-5-sulfonate and ethylene glycol into a pre-esterification kettle for pre-esterification;

(3) second esterification: adding a first esterification product, an isophthalic acid-5-sulfonate pre-esterification product, 2-methyl-1, 3-propanediol and a complex ether inhibitor into a second esterification kettle, wherein the addition amount of the 2-methyl-1, 3-propanediol is 0.5-30 wt% of the first esterification product, and carrying out second esterification;

(4) Pre-polycondensation: adding a second esterification product and polyethylene glycol into a pre-polycondensation kettle, wherein the addition amount of the polyethylene glycol is 0.5-30 wt% of that of the first esterification product, and performing pre-polycondensation;

2. The method for preparing moisture absorbable and breathable ECDP fiber according to claim 1, wherein:

in the step (1), the molar ratio of terephthalic acid to ethylene glycol is 1: 1.1-1.5; and/or

In the step (3), the addition amount of the m-phthalic acid-5-sulfonate pre-esterification product is 0.3-10 wt% of the first esterification product.

3. The method for preparing moisture absorbable and breathable ECDP fiber according to claim 1, wherein:

in the step (1), the catalyst is at least one of antimony trioxide, antimony acetate and ethylene glycol antimony, and the molar ratio of the terephthalic acid to the catalyst is 1: 0.0002-0.0004; and/or

In the step (3), the compound ether-proof agent is at least two of sodium acetate, disodium hydrogen phosphate, sodium dihydrogen phosphate, dipotassium hydrogen phosphate, potassium dihydrogen phosphate and phosphoric acid, and the addition amount of the compound ether-proof agent is 0.1-1 wt% of the first esterification product; and/or

In the step (4), the molecular weight of the polyethylene glycol is 1000-10000.

4. The method for preparing moisture absorbable and breathable ECDP fiber according to claim 1, wherein:

in the step (1), the first esterification is carried out at 230-255 ℃ and 40-60 kPa, and the esterification rate is controlled to be more than 80%; and/or

5. The method for preparing moisture absorption and sweat releasing ECDP fiber according to claim 1, wherein in step (4), polyethylene glycol is added into the pre-polycondensation kettle through a pipeline.

6. The method for preparing moisture absorption and sweat releasing ECDP fiber according to claim 1, wherein in step (6), the final polycondensation product and polypropylene are prepared into blended chips, and the specific steps are as follows: and fully mixing the final polycondensation product with polypropylene according to the mass ratio of 1: 0.02-0.05, then carrying out melt blending granulation by using a double-screw extruder, cooling and pelletizing.

7. The method for preparing moisture absorption and sweat releasing ECDP fiber according to claim 6, wherein in step (6), said polypropylene is modified polypropylene, and the preparation process is as follows:

(1) preparation of modified hydroxyethyl sulfate: dispersing vinyl sulfate into alcohol, adding a ring-opening catalyst, uniformly mixing, heating to 70-80 ℃, continuously dropwise adding glycidyl methacrylate at the temperature, continuously stirring until the reaction is finished, then recovering the ring-opening catalyst, and removing the alcohol and excessive glycidyl methacrylate by reduced pressure rotary evaporation;

(2) Preparing modified polypropylene: mixing propylene and modified hydroxyethyl sulfate according to a molar ratio of 1: 0.001-0.003, and polymerizing for 1-2 hours at 85-95 ℃ and 1.5-2.0 MPa.

8. The method for preparing moisture absorption and sweat releasing ECDP fiber according to claim 1, wherein in step (7), a trilobal spinneret is used to spray out the fiber during spinning.

9. The method for preparing moisture-absorbing and sweat-releasing ECDP fiber according to claim 8, wherein in the step (7), the spinneret plate hole length of the trilobal spinneret plate is 0.3-1.6 mm, and the leaf width is 0.1-0.8 mm.

10. The method for preparing moisture absorbable and breathable ECDP fiber according to claim 1, wherein:

in the step (7), the spinning temperature is 270-290 ℃, the speed is 1200-3000 m/min, and the air speed of blowing cooling after spinning is 1.5-2.5 m/min; and/or