CN114108120A - Melt direct-spinning porous superfine polyester fiber and preparation method thereof - Google Patents
Melt direct-spinning porous superfine polyester fiber and preparation method thereof Download PDFInfo
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- CN114108120A CN114108120A CN202111613109.9A CN202111613109A CN114108120A CN 114108120 A CN114108120 A CN 114108120A CN 202111613109 A CN202111613109 A CN 202111613109A CN 114108120 A CN114108120 A CN 114108120A
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- polyester fiber
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- 229920000728 polyester Polymers 0.000 title claims abstract description 109
- 239000000835 fiber Substances 0.000 title claims abstract description 82
- 238000010036 direct spinning Methods 0.000 title claims abstract description 29
- 238000002360 preparation method Methods 0.000 title abstract description 13
- KKEYFWRCBNTPAC-UHFFFAOYSA-N Terephthalic acid Chemical compound OC(=O)C1=CC=C(C(O)=O)C=C1 KKEYFWRCBNTPAC-UHFFFAOYSA-N 0.000 claims abstract description 129
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 claims abstract description 81
- 238000009987 spinning Methods 0.000 claims abstract description 67
- GOUHYARYYWKXHS-UHFFFAOYSA-N 4-formylbenzoic acid Chemical compound OC(=O)C1=CC=C(C=O)C=C1 GOUHYARYYWKXHS-UHFFFAOYSA-N 0.000 claims abstract description 47
- 238000005886 esterification reaction Methods 0.000 claims abstract description 45
- 239000012279 sodium borohydride Substances 0.000 claims abstract description 44
- 229910000033 sodium borohydride Inorganic materials 0.000 claims abstract description 44
- 239000000155 melt Substances 0.000 claims abstract description 41
- 238000000034 method Methods 0.000 claims abstract description 27
- 238000006243 chemical reaction Methods 0.000 claims abstract description 14
- 238000006068 polycondensation reaction Methods 0.000 claims abstract description 14
- WWYFPDXEIFBNKE-UHFFFAOYSA-N 4-(hydroxymethyl)benzoic acid Chemical compound OCC1=CC=C(C(O)=O)C=C1 WWYFPDXEIFBNKE-UHFFFAOYSA-N 0.000 claims abstract description 8
- 239000003381 stabilizer Substances 0.000 claims description 20
- 239000003054 catalyst Substances 0.000 claims description 17
- 238000001816 cooling Methods 0.000 claims description 16
- 238000004804 winding Methods 0.000 claims description 16
- ADCOVFLJGNWWNZ-UHFFFAOYSA-N antimony trioxide Chemical compound O=[Sb]O[Sb]=O ADCOVFLJGNWWNZ-UHFFFAOYSA-N 0.000 claims description 8
- 238000009998 heat setting Methods 0.000 claims description 8
- 238000002156 mixing Methods 0.000 claims description 8
- 239000002002 slurry Substances 0.000 claims description 8
- WSXIMVDZMNWNRF-UHFFFAOYSA-N antimony;ethane-1,2-diol Chemical compound [Sb].OCCO WSXIMVDZMNWNRF-UHFFFAOYSA-N 0.000 claims description 6
- WVLBCYQITXONBZ-UHFFFAOYSA-N trimethyl phosphate Chemical compound COP(=O)(OC)OC WVLBCYQITXONBZ-UHFFFAOYSA-N 0.000 claims description 6
- 239000012535 impurity Substances 0.000 claims description 5
- JVLRYPRBKSMEBF-UHFFFAOYSA-K diacetyloxystibanyl acetate Chemical compound [Sb+3].CC([O-])=O.CC([O-])=O.CC([O-])=O JVLRYPRBKSMEBF-UHFFFAOYSA-K 0.000 claims description 4
- 238000009826 distribution Methods 0.000 claims description 4
- CYTQBVOFDCPGCX-UHFFFAOYSA-N trimethyl phosphite Chemical compound COP(OC)OC CYTQBVOFDCPGCX-UHFFFAOYSA-N 0.000 claims description 4
- XZZNDPSIHUTMOC-UHFFFAOYSA-N triphenyl phosphate Chemical compound C=1C=CC=CC=1OP(OC=1C=CC=CC=1)(=O)OC1=CC=CC=C1 XZZNDPSIHUTMOC-UHFFFAOYSA-N 0.000 claims description 4
- 238000001914 filtration Methods 0.000 abstract description 10
- 230000015572 biosynthetic process Effects 0.000 abstract description 9
- 238000003786 synthesis reaction Methods 0.000 abstract description 9
- 230000032050 esterification Effects 0.000 abstract description 8
- 239000000126 substance Substances 0.000 abstract description 7
- 230000002035 prolonged effect Effects 0.000 abstract description 3
- 239000004744 fabric Substances 0.000 description 9
- 125000000524 functional group Chemical group 0.000 description 7
- -1 polyethylene terephthalate Polymers 0.000 description 5
- 230000035484 reaction time Effects 0.000 description 5
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 2
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 2
- WVDDGKGOMKODPV-UHFFFAOYSA-N hydroxymethyl benzene Natural products OCC1=CC=CC=C1 WVDDGKGOMKODPV-UHFFFAOYSA-N 0.000 description 2
- 238000009413 insulation Methods 0.000 description 2
- 229920000139 polyethylene terephthalate Polymers 0.000 description 2
- 239000005020 polyethylene terephthalate Substances 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 230000004580 weight loss Effects 0.000 description 2
- DYNFCHNNOHNJFG-UHFFFAOYSA-N 2-formylbenzoic acid Chemical compound OC(=O)C1=CC=CC=C1C=O DYNFCHNNOHNJFG-UHFFFAOYSA-N 0.000 description 1
- LLLVZDVNHNWSDS-UHFFFAOYSA-N 4-methylidene-3,5-dioxabicyclo[5.2.2]undeca-1(9),7,10-triene-2,6-dione Chemical compound C1(C2=CC=C(C(=O)OC(=C)O1)C=C2)=O LLLVZDVNHNWSDS-UHFFFAOYSA-N 0.000 description 1
- 229920001410 Microfiber Polymers 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 238000007259 addition reaction Methods 0.000 description 1
- 150000001408 amides Chemical class 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 235000019445 benzyl alcohol Nutrition 0.000 description 1
- 230000001588 bifunctional effect Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000004043 dyeing Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000005984 hydrogenation reaction Methods 0.000 description 1
- 239000002932 luster Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000002074 melt spinning Methods 0.000 description 1
- 239000003658 microfiber Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
- 150000003138 primary alcohols Chemical class 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 150000003333 secondary alcohols Chemical class 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
- D01F6/58—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products
- D01F6/62—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products from polyesters
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
- C08G63/02—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds
- C08G63/12—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds derived from polycarboxylic acids and polyhydroxy compounds
- C08G63/16—Dicarboxylic acids and dihydroxy compounds
- C08G63/18—Dicarboxylic acids and dihydroxy compounds the acids or hydroxy compounds containing carbocyclic rings
- C08G63/181—Acids containing aromatic rings
- C08G63/183—Terephthalic acids
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
- C08G63/78—Preparation processes
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
- D01D1/00—Treatment of filament-forming or like material
- D01D1/06—Feeding liquid to the spinning head
- D01D1/09—Control of pressure, temperature or feeding rate
Abstract
The invention relates to a melt direct spinning porous superfine polyester fiber and a preparation method thereof, wherein sodium borohydride is added in esterification reaction of terephthalic acid and ethylene glycol, and the melt direct spinning porous superfine polyester fiber is obtained through polycondensation reaction and spinning process after the esterification reaction; the addition amount of the sodium borohydride is 30-50ppm of the weight of the terephthalic acid, and due to the characteristics and chemical selectivity of sodium borohydride reaction, the sodium borohydride reacts with p-carboxybenzaldehyde in the terephthalic acid before esterification in polyester synthesis to generate p-carboxybenzyl alcohol, so that a net structure formed by the p-carboxybenzaldehyde in the polyester synthesis process is eliminated, the filtering performance of a polyester melt is improved, the quality of the porous superfine polyester fiber is ensured, the replacement period of a filter and a spinning assembly is prolonged, and the prepared melt direct-spun porous superfine polyester fiber has excellent breaking strength and breaking elongation.
Description
Technical Field
The invention relates to a melt direct-spinning porous superfine polyester fiber and a preparation method thereof, belonging to the field of polyester spinning.
Background
Porous superfine fiber is a main development stream of the differential fiber at present and is an important product in the development of the differential fiber. The fabric made of the porous superfine fiber has the characteristics and style which are incomparable with the conventional chemical fiber and natural fiber, wherein the most prominent is good softness and silk feeling.
Due to the fine structure of the porous superfine fibers, the number of the fibers in the fabric is increased, so that a micro air chamber effect is brought, and the heat preservation and the heat insulation performance and the sound insulation performance of the fabric are improved. And the porous superfine fiber has large specific surface area, is favorable for improving the moisture absorption of the fabric, has obvious and special capillary phenomenon for conveying and guiding water vapor, has good performance, and not only can improve the dyeing performance of the fabric, but also improves the comfort of wearing. The porous superfine chemical fiber clothing fabric has better softness, dimensional stability and drapability than common fabrics.
At present, the porous superfine polyester fabric has many excellent characteristics, such as soft hand feeling, drapability, soft luster, air permeability, moisture transmission, wind resistance, water repellency and the like, and plays an important role in the porous superfine fiber fabric.
The spinning melt direct spinning porous superfine polyester fiber has high requirement on polyester melt, moderate molecular weight and small distribution, less impurities in the melt and less gel content. And the viscosity reduction of the polyester melt from the outlet to the spinning beam is small, namely the thermal stability is good. The filter and spin pack assembly require high filtration accuracy and must filter all particles in excess of the diameter of the microfibers.
In the existing preparation method, in order to improve the quality of the melt direct-spun porous superfine polyester fiber, the filtering precision of a filter and a spinning assembly is very high, but because terephthalic acid contains a certain amount of p-carboxybenzaldehyde, the replacement period of the filter and the spinning assembly is short, and the quality of the prepared melt direct-spun porous superfine polyester fiber is also influenced.
Disclosure of Invention
The invention aims to provide a preparation method of melt direct-spun porous superfine polyester fiber, wherein the replacement period of a filter and a spinning component is long, and the obtained melt direct-spun porous superfine polyester fiber has good quality.
In order to achieve the purpose, the invention provides the following technical scheme: a method for preparing melt direct spinning porous superfine polyester fiber, adding sodium borohydride in esterification reaction of terephthalic acid and ethylene glycol, and obtaining melt direct spinning porous superfine polyester fiber through polycondensation reaction and spinning process after esterification reaction;
wherein, the terephthalic acid contains p-carboxybenzaldehyde as an impurity, and the sodium borohydride reduces the p-carboxybenzaldehyde into p-carboxybenzyl alcohol;
the adding amount of the sodium borohydride is 30-50ppm of the weight of the terephthalic acid.
Further, the preparation method comprises the following steps:
s1, preparing terephthalic acid and ethylene glycol into slurry, adding sodium borohydride, a catalyst and a stabilizer, uniformly mixing, and then carrying out esterification reaction at the temperature of 200-260 ℃ for 120-180min, wherein in the esterification reaction process, the temperature is gradually increased from 200 ℃ to 260 ℃ and is finally maintained at 260 ℃;
s2, after the esterification reaction is finished, carrying out polycondensation reaction under the negative pressure condition of the absolute pressure of less than 80Pa, wherein the reaction temperature is 275-;
s3, preparing the melt direct spinning porous superfine polyester fiber from the polyester through a spinning process.
Further, in the step S1, the molar ratio of the terephthalic acid to the ethylene glycol is 1: 1.3-1.5; the addition amount of the catalyst is 0.01 to 0.02 percent of the weight of the terephthalic acid; the adding amount of the sodium borohydride is 30-50ppm of the weight of the terephthalic acid; the addition amount of the stabilizer is 0.01-0.03% of the weight of the terephthalic acid.
Further, in the step S1, the catalyst is any one of antimony trioxide, ethylene glycol antimony or antimony acetate; the stabilizer is any one of triphenyl phosphate, trimethyl phosphate or trimethyl phosphite.
Further, the spinning process includes metering, extruding, cooling, oiling, stretching, heat setting, and winding.
Further, in the spinning process, the initial pressure of the spinning assembly is 130 bar; the pressure rise delta P of the spinning assembly is less than or equal to 0.6 bar/day.
Further, the spinning process parameters are as follows:
spinning temperature: 290 ℃ and 295 ℃;
cooling temperature: 20-25 ℃;
network pressure: 0.20-0.30 MPa;
a roll speed: 3200-3300m/min
First roll temperature: 85-90 ℃;
two roll speed: 4000-;
temperature of the two rolls: 120 ℃ to 130 ℃;
speed of winding: 3950 and 4150 m/min.
Further, the number average molecular weight of the polyester is 22000-25000g/mol, and the molecular weight distribution index is 1.8-2.1.
Further, the filament number of the melt direct-spun porous superfine polyester fiber is 0.2-0.3 dtex; the number of spinneret orifices of the spinneret plate is more than or equal to 96; the number of broken filaments of one spinning cake of the melt direct-spinning porous superfine polyester fiber is less than or equal to 2; the melt direct-spinning porous superfine polyester fiber has breaking strength of more than or equal to 3.5cN/dtex, elongation at break of 40.0 +/-3.0%, CV value of breaking strength of less than or equal to 5.0% and CV value of elongation at break of less than or equal to 10.0%.
The invention also provides a melt direct-spun porous superfine polyester fiber prepared by the preparation method of the melt direct-spun porous superfine polyester fiber.
The invention has the beneficial effects that:
1. when the melt direct-spinning porous superfine polyester fiber is prepared, sodium borohydride is added in the esterification reaction of terephthalic acid and ethylene glycol, and the sodium borohydride reacts with p-carboxybenzaldehyde in the terephthalic acid before esterification in the polyester synthesis to generate p-carboxybenzyl alcohol due to the characteristics and chemical selectivity of the sodium borohydride reaction, so that a net structure formed by the p-carboxybenzaldehyde in the polyester synthesis process is eliminated, the filtering performance of the polyester melt is improved, the quality of the melt direct-spinning porous superfine polyester fiber is ensured, and the replacement period of a filter and a spinning assembly is prolonged.
2. The melt direct-spun porous superfine polyester fiber prepared by the method has excellent breaking strength and breaking elongation.
The foregoing is a summary of the present invention, and in order to provide a clear understanding of the technical means of the present invention and to be implemented in accordance with the present specification, the following is a detailed description of the preferred embodiments of the present invention.
Detailed Description
The technical solutions of the present invention will be described clearly and completely below, and it should be apparent that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
The invention aims to improve the quality of melt direct-spun porous superfine polyester fibers and prolong the service life of the replacement of a filter and a spinning assembly. The reason for the short cycle time of the filter and spin pack assembly was first analyzed.
In the prior art, the melt direct spinning porous superfine polyester fiber is prepared by melt spinning polyethylene terephthalate (PET), which is a polycondensation Product of Terephthalic Acid (PTA) and Ethylene Glycol (EG). However, in the case of terephthalic acid, which contains p-carboxybenzaldehyde (4-CBA) as a by-product in the production process, a small amount of p-carboxybenzaldehyde remains in the terephthalic acid, sometimes in the range of about 50 to 100ppm, and sometimes 130ppm, although the p-carboxybenzaldehyde is reduced by hydrogenation during the purification of terephthalic acid.
In the polyester preparation reaction by polycondensation, p-carboxybenzaldehyde can react with ethylene glycol to generate p-carboxybenzaldehyde diethylene glycol which is an organic molecule with three functional groups, two functional groups are hydroxyl groups, and the third functional group is carboxyl group.
Specifically, the formed smaller network structure affects the quality of the porous superfine polyester fiber, mainly reflected in that the CV value of the breaking strength and the CV value of the elongation at break have certain changes, and the breaking strength is also reduced. The breaking strength of the porous superfine polyester fiber obtained at present is more than or equal to 3.4cN/dtex, the elongation at break is 40.0 +/-6.0 percent, the CV value of the breaking strength is less than or equal to 7.0 percent, and the CV value of the elongation at break is less than or equal to 12.0 percent.
The formed larger net structure forms infusible gel, which causes difficult filtration, influences the filtration performance of the polyester and reduces the service cycle of the filter and the spinning assembly.
Meanwhile, the carboxybenzaldehyde can also perform addition reaction with other substances to generate unsaturated double bonds, which affects the thermal property of the polyester and causes the reduction of the thermal stability of the polyester.
The invention provides a preparation method of melt direct-spinning porous superfine polyester fiber, which comprises the steps of adding sodium borohydride into esterification reaction of terephthalic acid and ethylene glycol, and obtaining the melt direct-spinning porous superfine polyester fiber through polycondensation reaction and spinning process after the esterification reaction.
Specifically, the preparation method comprises the following steps:
s1, preparing terephthalic acid and ethylene glycol into slurry, adding sodium borohydride, a catalyst and a stabilizer, uniformly mixing, and then carrying out esterification reaction at the temperature of 200-260 ℃ for 120-180min, wherein in the esterification reaction process, the temperature is gradually increased from 200 ℃ to 260 ℃ and is finally maintained at 260 ℃;
s2, after the esterification reaction is finished, carrying out polycondensation reaction under the negative pressure condition of the absolute pressure of less than 80Pa, wherein the reaction temperature is 275-;
s3, preparing the melt direct spinning porous superfine polyester fiber from the polyester through a spinning process.
In the above, terephthalic acid contains p-carboxybenzaldehyde as an impurity, and sodium borohydride reduces p-carboxybenzaldehyde to p-carboxybenzyl alcohol.
Specifically, sodium borohydride can reduce aldehyde carbonyl and ketone carbonyl under very mild conditions to generate primary alcohol and secondary alcohol. Sodium borohydride is a reducing agent with medium strength, shows good chemoselectivity in the reaction, and only reduces active aldehyde carbonyl and ketone carbonyl, but does not react with ester and amide.
Sodium borohydride has no influence on ester bonds in the polyester synthesis, and the stability of the ester bonds is ensured. Due to the characteristics and chemical selectivity of sodium borohydride reaction, the sodium borohydride and p-carboxybenzaldehyde react before esterification reaction in polyester synthesis to generate p-carboxybenzyl alcohol.
The p-carboxyl benzyl alcohol is a bifunctional molecule, and can perform esterification reaction on terephthalic acid and ethylene glycol to form linear molecules, so that a reticular structure formed by p-carboxyl benzaldehyde in a polyester synthesis process is eliminated, the filtering performance of a polyester melt is improved, and the quality of the porous superfine fiber is ensured.
Wherein the adding amount of the sodium borohydride is 30-50ppm of the weight of the terephthalic acid. The amount of sodium borohydride added is based on the amount of p-carboxybenzaldehyde in the terephthalic acid. The low efficiency of removing p-carboxybenzaldehyde is caused by the low addition amount of sodium borohydride, and the waste and the introduction of impurities are caused by the excessive addition amount of sodium borohydride.
In step S1, the molar ratio of terephthalic acid to ethylene glycol is 1: 1.3-1.5; the addition amount of the catalyst is 0.01 to 0.02 percent of the weight of the terephthalic acid; the adding amount of the sodium borohydride is 30-50ppm of the weight of the terephthalic acid; the addition amount of the stabilizer is 0.01-0.03% of the weight of the terephthalic acid.
In step S1, the catalyst is any one of antimony trioxide, ethylene glycol antimony, or antimony acetate; the stabilizer is any one of triphenyl phosphate, trimethyl phosphate or trimethyl phosphite.
Wherein, the addition of the stabilizer can effectively reduce the side reaction in the esterification reaction process of the polyester.
The spinning process includes metering, extruding, cooling, oiling, stretching, heat setting and winding. The spinning process is prior art and is not described herein.
The spinning process parameters are as follows:
spinning temperature: 290 ℃ and 295 ℃;
cooling temperature: 20-25 ℃;
network pressure: 0.20-0.30 MPa;
a roll speed: 3200-3300m/min
First roll temperature: 85-90 ℃;
two roll speed: 4000-;
temperature of the two rolls: 120 ℃ to 130 ℃;
speed of winding: 3950 and 4150 m/min.
The initial pressure of the spinning assembly is 130bar, the pressure rise delta P of the spinning assembly is less than or equal to 0.60 bar/day, and the service cycle of the spinning assembly is more than 40 days. Compared with the service life of the spinning assembly and the filter in the prior art, the service life of the spinning assembly and the filter is prolonged by 10-15 days by 25-30 days.
In this embodiment, the polyester obtained in step S2 has a number average molecular weight of 22000-25000g/mol and a molecular weight distribution index of 1.8-2.1.
The monofilament titer of the melt direct-spun porous superfine polyester fiber obtained in the step S3 is 0.2-0.3 dtex; the number of spinneret orifices of the spinneret plate is more than or equal to 96; the number of broken filaments of one spinning cake of the melt direct spinning porous superfine polyester fiber is less than or equal to 2; the breaking strength is more than or equal to 3.5cN/dtex, the elongation at break is 40.0 +/-3.0%, the CV value of the breaking strength is less than or equal to 5.0%, and the CV value of the elongation at break is less than or equal to 10.0%.
Compared with the melt direct-spun porous superfine polyester fiber obtained in the prior art, the melt direct-spun porous superfine polyester fiber obtained in the embodiment has improved quality, and is mainly reflected in that the CV value of the breaking strength and the CV value of the elongation at break are improved.
The temperature of 5 percent of thermal weight loss of the melt direct-spun porous superfine polyester fiber obtained by the prior art is about 290 ℃, and the temperature of 5 percent of thermal weight loss of the melt direct-spun porous superfine polyester fiber obtained by the invention is more than 295 ℃, so that the melt direct-spun porous superfine polyester fiber obtained by the invention is proved to have high thermal stability.
The above-mentioned preparation process is described in detail below with specific examples.
Example one
Step one, preparing terephthalic acid and ethylene glycol into slurry, adding sodium borohydride, a catalyst and a stabilizer, uniformly mixing, and then carrying out esterification reaction at the temperature of 220-260 ℃ for 120 min. During the esterification reaction, the esterification temperature is a process of gradually increasing the temperature, and the temperature is gradually increased from 200 ℃ to 260 ℃ and is finally maintained at 260 ℃.
The molar ratio of terephthalic acid to ethylene glycol is 1: 1.3;
the adding amount of the catalyst antimony trioxide is 0.01 percent of the weight of the terephthalic acid; the addition amount of sodium borohydride is 30ppm of the weight of terephthalic acid; the amount of triphenyl phosphate as a stabilizer added was 0.01% by weight of terephthalic acid.
And step two, after the esterification reaction is finished, carrying out polycondensation reaction under the negative pressure condition of the absolute pressure of less than 80Pa, wherein the reaction temperature is 275 ℃, and the reaction time is 150min, thus obtaining the polyester.
Thirdly, preparing melt direct spinning porous superfine polyester fiber from polyester through metering, extruding, cooling, oiling, stretching, heat setting and winding, wherein the spinning process parameters are as follows:
spinning temperature: 290 ℃;
cooling temperature: 20 ℃;
network pressure: 0.20 MPa;
a roll speed: 3200m/min
First roll temperature: 85 ℃;
two roll speed: 4000 m/min;
temperature of the two rolls: 120 ℃;
speed of winding: 3950 m/min.
In the spinning process, due to the addition of sodium borohydride, p-carboxybenzaldehyde contained in terephthalic acid is reduced into p-carboxybenzyl alcohol, so that the filtering performance of the polyester melt and the quality of the melt direct-spinning porous superfine polyester fiber are effectively improved. In addition, the pressure rise of the spinning assembly and the filter is effectively reduced, wherein the pressure rise delta P of the spinning assembly is 0.53 bar/day, and the service life of the spinning assembly is 47 days.
The filament number of the melt direct-spun porous superfine polyester fiber obtained in the step is 0.2dtex, and the number of the spinneret holes of the spinneret plate is 96; one cake had 2 broken filaments, a breaking strength of 3.5cN/dtex, an elongation at break of 43.0%, a CV value for breaking strength of 4.7%, and a CV value for elongation at break of 9.5%.
Example two
Step one, preparing terephthalic acid and ethylene glycol into slurry, adding sodium borohydride, a catalyst and a stabilizer, uniformly mixing, and then carrying out esterification reaction at the temperature of 220-260 ℃ for 180 min. During the esterification reaction, the esterification temperature is a process of gradually increasing the temperature, and the temperature is gradually increased from 200 ℃ to 260 ℃ and is finally maintained at 260 ℃.
The molar ratio of terephthalic acid to ethylene glycol is 1: 1.5;
the addition amount of the catalyst ethylene glycol antimony is 0.02 percent of the weight of the terephthalic acid; the addition amount of sodium borohydride is 50ppm of the weight of terephthalic acid; the amount of trimethyl phosphate added as a stabilizer was 0.03% by weight based on the weight of terephthalic acid.
And step two, after the esterification reaction is finished, carrying out polycondensation reaction under the negative pressure condition of the absolute pressure of less than 80Pa, wherein the reaction temperature is 283 ℃, and the reaction time is 150min, thus preparing the polyester.
Thirdly, preparing melt direct spinning porous superfine polyester fiber from polyester through metering, extruding, cooling, oiling, stretching, heat setting and winding, wherein the spinning process parameters are as follows:
spinning temperature: 292 deg.C;
cooling temperature: 22 ℃;
network pressure: 0.25 MPa;
a roll speed: 3250m/min
First roll temperature: 88 ℃;
two roll speed: 4100 m/min;
temperature of the two rolls: 125 ℃;
speed of winding: 4050 m/min.
The pressure rise Δ P of the spinning pack is 0.54 bar/day, and the service life of the spinning pack is 46 days.
The filament number of the melt direct-spun porous superfine polyester fiber obtained in the step is 0.3dtex, and the number of the spinneret holes of a spinneret plate is 108; one cake had 1 broken filament, a breaking strength of 3.68cN/dtex, an elongation at break of 37%, a CV value of breaking strength of 5.0%, and a CV value of elongation at break of 9.1%.
EXAMPLE III
Step one, preparing ethylene terephthalate into slurry, adding sodium borohydride and a stabilizer, uniformly mixing, and then carrying out esterification reaction at the temperature of 220-260 ℃ for 180 min. During the esterification reaction, the esterification temperature is a process of gradually increasing the temperature, and the temperature is gradually increased from 200 ℃ to 260 ℃ and is finally maintained at 260 ℃.
The molar ratio of terephthalic acid to ethylene glycol is 1: 1.4;
the addition amount of the catalyst ethylene glycol antimony is 0.02 percent of the weight of the terephthalic acid; the adding amount of the sodium borohydride is 40ppm of the weight of the terephthalic acid; the amount of trimethyl phosphate added as a stabilizer was 0.02% by weight based on the weight of terephthalic acid.
And step two, after the esterification reaction is finished, carrying out polycondensation reaction under the negative pressure condition of the absolute pressure of less than 80Pa, wherein the reaction temperature is 280 ℃, and the reaction time is 130min, thus obtaining the polyester.
Thirdly, preparing melt direct spinning porous superfine polyester fiber from polyester through metering, extruding, cooling, oiling, stretching, heat setting and winding, wherein the spinning process parameters are as follows:
spinning temperature: 293 ℃;
cooling temperature: 22 ℃;
network pressure: 0.25 MPa;
a roll speed: 3300m/min
First roll temperature: 90 ℃;
two roll speed: 4200 m/min;
temperature of the two rolls: 130 ℃;
speed of winding: 4150 m/min.
The pressure rise Δ P of the spinning pack is 0.55 bar/day, and the service life of the spinning pack is 45 days.
The filament number of the melt direct-spun porous superfine polyester fiber obtained in the step is 0.25dtex, and the number of the spinneret holes of the spinneret plate is 120; one spinning cake had 1 single broken filament, 3.56cN/dtex breaking strength, 40.0% elongation at break, 4.8% CV value of breaking strength and 9.0% CV value of elongation at break.
Example four
Step one, preparing terephthalic acid and ethylene glycol into slurry, adding sodium borohydride and a stabilizer, uniformly mixing, and then carrying out esterification reaction at the temperature of 220-260 ℃ for 180 min. During the esterification reaction, the esterification temperature is a process of gradually increasing the temperature, and the temperature is gradually increased from 200 ℃ to 260 ℃ and is finally maintained at 260 ℃.
The molar ratio of terephthalic acid to ethylene glycol is 1: 1.5;
the adding amount of the catalyst antimony acetate is 0.01 percent of the weight of the terephthalic acid; the adding amount of the sodium borohydride is 40ppm of the weight of the terephthalic acid; the stabilizer trimethyl phosphite is added in an amount of 0.03% by weight based on the weight of terephthalic acid.
And step two, after the esterification reaction is finished, carrying out polycondensation reaction under the negative pressure condition of the absolute pressure of less than 80Pa, wherein the reaction temperature is 283 ℃, and the reaction time is 100min, thus preparing the polyester.
Thirdly, preparing melt direct spinning porous superfine polyester fiber from polyester through metering, extruding, cooling, oiling, stretching, heat setting and winding, wherein the spinning process parameters are as follows:
spinning temperature: 295 ℃;
cooling temperature: 20 ℃;
network pressure: 0.30 MPa;
a roll speed: 3200m/min
First roll temperature: 85 ℃;
two roll speed: 4000 m/min;
temperature of the two rolls: 125 ℃;
speed of winding: 4000 m/min.
The pressure rise Δ P of the spinning pack is 0.60 bar/day, and the service life of the spinning pack is 42 days.
The filament number of the melt direct-spun porous superfine polyester fiber obtained in the step is 0.3dtex, and the number of the spinneret holes of a spinneret plate is 108; one spinning cake had 1 broken filament, 3.66cN/dtex breaking strength, 42.0% elongation at break, 4.2% CV value of breaking strength and 9.3% CV value of elongation at break.
Comparative example 1
Without addition of sodium borohydride
Step one, preparing terephthalic acid and ethylene glycol into slurry, adding a catalyst and a stabilizer, uniformly mixing, and then carrying out esterification reaction at the temperature of 220 ℃ and 260 ℃ for 180 min. During the esterification reaction, the esterification temperature is a process of gradually increasing the temperature, and the temperature is gradually increased from 200 ℃ to 260 ℃ and is finally maintained at 260 ℃.
The molar ratio of terephthalic acid to ethylene glycol is 1: 1.4;
the addition amount of the catalyst ethylene glycol antimony is 0.02 percent of the weight of the terephthalic acid; the amount of trimethyl phosphate added as a stabilizer was 0.02% by weight based on the weight of terephthalic acid.
And step two, after the esterification reaction is finished, carrying out polycondensation reaction under the negative pressure condition of the absolute pressure of less than 80Pa, wherein the reaction temperature is 280 ℃, and the reaction time is 130min, thus obtaining the polyester.
Thirdly, preparing melt direct spinning porous superfine polyester fiber from polyester through metering, extruding, cooling, oiling, stretching, heat setting and winding, wherein the spinning process parameters are as follows:
spinning temperature: 293 ℃;
cooling temperature: 22 ℃;
network pressure: 0.25 MPa;
a roll speed: 3300m/min
First roll temperature: 90 ℃;
two roll speed: 4200 m/min;
temperature of the two rolls: 130 ℃;
speed of winding: 4150 m/min.
In the spinning process, due to the fact that sodium borohydride is not added, p-carboxybenzaldehyde contained in terephthalic acid can react with ethylene glycol to generate p-carboxybenzaldehyde diethylene glycol, the p-carboxybenzaldehyde diethylene glycol is an organic molecule with three functional groups, two functional groups are hydroxyl groups, a third functional group is carboxyl, and the three functional groups can respectively react with the terephthalic acid and the ethylene glycol to form a net structure and generate insoluble gel, so that the quality of the porous superfine polyester fiber is influenced, and the filtering performance of the polyester is influenced.
Wherein the pressure rise deltap of the spinning pack is 0.88 bar/day and the service life of the spinning pack is 28 days.
The filament number of the melt direct-spun porous superfine polyester fiber obtained in the step is 0.25dtex, and the number of the spinneret holes of the spinneret plate is 120; one cake had 3 broken filaments, a breaking strength of 3.38cN/dtex, an elongation at break of 47.0%, a CV value for breaking strength of 6.8%, and a CV value for elongation at break of 12.0%.
The invention also provides the melt direct-spun porous superfine polyester fiber prepared by the preparation method of the melt direct-spun porous superfine polyester fiber, and the performances of the obtained melt direct-spun porous superfine polyester fiber are described above, and are not described again.
In summary, in the invention, when preparing the melt direct-spun porous superfine polyester fiber, sodium borohydride is added in the esterification reaction of terephthalic acid and ethylene glycol, and due to the characteristics and chemical selectivity of the sodium borohydride reaction, the sodium borohydride reacts with p-carboxybenzaldehyde in the terephthalic acid before esterification in the polyester synthesis to generate p-carboxybenzyl alcohol, thereby eliminating a net structure formed by the p-carboxybenzaldehyde in the polyester synthesis process, improving the filtration performance of the polyester melt, ensuring the quality of the superfine fiber, and prolonging the replacement period of a filter and a spinning assembly.
2. The melt direct-spun porous superfine polyester fiber prepared by the method has excellent breaking strength and breaking elongation.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (10)
1. A method for preparing melt direct spinning porous superfine polyester fiber is characterized in that sodium borohydride is added in esterification reaction of terephthalic acid and ethylene glycol, and after esterification reaction, the melt direct spinning porous superfine polyester fiber is obtained through polycondensation reaction and spinning process;
wherein, the terephthalic acid contains p-carboxybenzaldehyde as an impurity, and the sodium borohydride reduces the p-carboxybenzaldehyde into p-carboxybenzyl alcohol;
the addition amount of the sodium borohydride is 30-50ppm of the weight of the terephthalic acid.
2. The method for preparing the melt-spun porous ultrafine polyester fiber according to claim 1, wherein the method comprises:
s1, preparing terephthalic acid and ethylene glycol into slurry, adding sodium borohydride, a catalyst and a stabilizer, uniformly mixing, and then carrying out esterification reaction at the temperature of 200-260 ℃ for 120-180min, wherein in the esterification reaction process, the temperature is gradually increased from 200 ℃ to 260 ℃ and is finally maintained at 260 ℃;
s2, after the esterification reaction is finished, carrying out polycondensation reaction under the negative pressure condition of the absolute pressure of less than 80Pa, wherein the reaction temperature is 275-;
s3, preparing the melt direct spinning porous superfine polyester fiber from the polyester through a spinning process.
3. The method for preparing melt-spun porous ultrafine polyester fiber according to claim 2, wherein in the step S1, the molar ratio of terephthalic acid to ethylene glycol is 1: 1.3-1.5; the addition amount of the catalyst is 0.01 to 0.02 percent of the weight of the terephthalic acid; the adding amount of the sodium borohydride is 30-50ppm of the weight of the terephthalic acid; the addition amount of the stabilizer is 0.01-0.03% of the weight of the terephthalic acid.
4. The method for preparing the melt-spun porous superfine polyester fiber according to claim 2, wherein in the step S1, the catalyst is any one of antimony trioxide, ethylene glycol antimony or antimony acetate; the stabilizer is any one of triphenyl phosphate, trimethyl phosphate or trimethyl phosphite.
5. The method of claim 2, wherein the spinning process comprises metering, extruding, cooling, oiling, drawing, heat setting, and winding.
6. The method for preparing melt-spun porous ultrafine polyester fiber according to claim 2, wherein in the spinning process, the initial pressure of the spinning pack is 130 bar; the pressure rise delta P of the spinning assembly is less than or equal to 0.6 bar/day.
7. The method for preparing the melt direct-spun porous superfine polyester fiber according to claim 2, wherein the spinning process parameters are as follows:
spinning temperature: 290 ℃ and 295 ℃;
cooling temperature: 20-25 ℃;
network pressure: 0.20-0.30 MPa;
a roll speed: 3200-3300m/min
First roll temperature: 85-90 ℃;
two roll speed: 4000-;
temperature of the two rolls: 120 ℃ to 130 ℃;
speed of winding: 3950 and 4150 m/min.
8. The method for preparing the melt-spun porous ultrafine polyester fiber as claimed in claim 2, wherein the number average molecular weight of the polyester is 22000-25000g/mol, and the molecular weight distribution index is 1.8-2.1.
9. The method for preparing melt-spun porous ultrafine polyester fiber according to claim 1 or 2, wherein the melt-spun porous ultrafine polyester fiber has a single-filament fineness of 0.2 to 0.3 dtex; the number of spinneret orifices of the spinneret plate is more than or equal to 96; the number of broken filaments of one spinning cake of the melt direct-spinning porous superfine polyester fiber is less than or equal to 2; the melt direct-spinning porous superfine polyester fiber has breaking strength of more than or equal to 3.5cN/dtex, elongation at break of 40.0 +/-3.0%, CV value of breaking strength of less than or equal to 5.0% and CV value of elongation at break of less than or equal to 10.0%.
10. A melt direct-spun porous ultrafine polyester fiber, which is prepared by the method for preparing the melt direct-spun porous ultrafine polyester fiber according to any one of claims 1 to 9.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3855275A (en) * | 1971-04-30 | 1974-12-17 | Halcon International Inc | Treatment of terephthalic acid reaction |
| CN101195571A (en) * | 2007-12-18 | 2008-06-11 | 盛虹集团有限公司 | Technique for reducing PT acid content in PTA product |
| CN105926060A (en) * | 2016-06-12 | 2016-09-07 | 福建百宏聚纤科技实业有限公司 | Melt direct spinning superfine denier polyester filament and making method thereof |
| CN110760058A (en) * | 2019-11-05 | 2020-02-07 | 杭州栋华实业投资有限公司 | Production process and application method of cationic polyester melt |
-
2021
- 2021-12-27 CN CN202111613109.9A patent/CN114108120A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3855275A (en) * | 1971-04-30 | 1974-12-17 | Halcon International Inc | Treatment of terephthalic acid reaction |
| CN101195571A (en) * | 2007-12-18 | 2008-06-11 | 盛虹集团有限公司 | Technique for reducing PT acid content in PTA product |
| CN105926060A (en) * | 2016-06-12 | 2016-09-07 | 福建百宏聚纤科技实业有限公司 | Melt direct spinning superfine denier polyester filament and making method thereof |
| CN110760058A (en) * | 2019-11-05 | 2020-02-07 | 杭州栋华实业投资有限公司 | Production process and application method of cationic polyester melt |
Non-Patent Citations (1)
| Title |
|---|
| 曹鸿林主编: "《合成纤维单体工艺学》", vol. 1, 纺织工业出版社出版, pages: 274 * |
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