CN111848938A

CN111848938A - Modified polyester, preparation method thereof and application of modified polyester as summer quilt fabric

Info

Publication number: CN111848938A
Application number: CN201910338184.5A
Authority: CN
Inventors: 王若南
Original assignee: South Bedding Technology Co ltd
Current assignee: South Bedding Technology Co ltd
Priority date: 2019-04-25
Filing date: 2019-04-25
Publication date: 2020-10-30
Anticipated expiration: 2039-04-25
Also published as: CN111848938B

Abstract

The invention discloses modified polyester, a preparation method thereof and application of the modified polyester as a summer quilt fabric. The modified polyester comprises the following raw materials: terephthalic acid, ethylene glycol, titanium-silicon-cobalt composite catalyst and modified components; the molar ratio of the titanium-silicon-cobalt composite catalyst to the ethylene glycol is (0.000005-0.002): 1; the modified component comprises polyethylene glycol, a sheet conductive material and a rod conductive material, and the mass ratio of the modified component to terephthalic acid is (0.005-0.2): 1. the modified polyester prepared by the invention has small surface contact angle and good moisture absorption performance; the polyester fiber prepared from the modified polyester has the advantages of moisture absorption performance, quick drying performance, softness and good antistatic performance, and can maintain excellent mechanical properties of the polyester fiber and excellent comprehensive performance.

Description

Modified polyester, preparation method thereof and application of modified polyester as summer quilt fabric

Technical Field

The invention relates to the technical field of polyester, in particular to modified polyester, a preparation method thereof and application of the modified polyester as a summer quilt fabric.

Background

In 2011, the yield of polyester fibers in China is 2795 million tons, which accounts for 83 percent of the yield of chemical fibers in China; accounting for 70% of the world's polyester fiber production. Although the polyester productivity and yield of China are the first in the world, the polyester fiber industry of China still faces some outstanding problems which need to be solved urgently: the product structure is unreasonable, the homogenization competition is intense, and the profit rate of the industry is low. Under the condition, polyester products with high added values are developed and produced, and energy conservation and cost reduction are subjects of development of polyester enterprises in the future. Meanwhile, along with the continuous development of economy, people put forward higher requirements on the comfort of clothes, and the improvement of scientific technology provides possibility for improving the comfort of textiles.

The polyester fiber is the most widely applied variety in the current synthetic fiber, but because the molecular structure arrangement of the polyester is regular, the crystallinity is high, the modulus is large, the fiber used in the clothing field has the problem of hard hand feeling, and the comfort is influenced; meanwhile, polyester molecules lack polar hydrophilic functional groups, and the moisture absorption of the fiber is poor. The hard hand feeling and poor hygroscopicity of polyester fibers restrict the further development of polyester technology in many occasions. Researchers are always striving to pursue the goal of preparing a fiber which has the advantages of moisture absorption performance, quick drying performance, softness performance and the like and simultaneously has the excellent mechanical properties of polyester fiber.

Among the factors that affect the comfort of polyester fibers, moisture absorption performance is one of the keys. The moisture absorption performance of the polyester fiber comprises the moisture absorption of gaseous moisture and the moisture absorption of liquid moisture, wherein the moisture absorption of the gaseous moisture is mainly determined by the chemical structure of the fiber, the physical structure can improve the moisture conduction performance of the fiber but has small influence on the gaseous moisture absorption, and the fiber with good gaseous moisture absorption also has good antistatic performance. Therefore, the improvement of the gas hygroscopicity of the polyester fiber is beneficial to textile processing, and simultaneously, the comfortable performance of the fiber is greatly improved. The liquid hygroscopicity of the fiber is influenced by the chemical structure, and has important relation with the physical structure and the morphological structure of the fiber.

Such as:

benzene rings in conventional polyester molecular chains form a rigid skeleton, and are lack of flexible macromolecules, so that the polyester fibers have hard handfeel, and the comfortableness of the polyester fibers is seriously influenced in the field of clothing fibers;

polyester fiber molecular chains lack polar functional groups, have poor hygroscopicity, are worn in the field of clothing, and are easy to generate stuffy feeling, and natural cellucotton fiber molecular chains contain a large amount of hydroxyl functional groups;

the polyester fiber is lack of polar functional groups in molecular chains, so that electrostatic aggregation is easily generated, dust adsorption is caused, and the anti-fouling capability is reduced;

the conventional polyester fiber has regular molecular chain arrangement, high crystallinity and lack of polar functional groups, dye molecules are difficult to enter a crystal region, the fiber dyeing needs to be carried out under the conditions of high temperature and high pressure, and the dyeing performance is mainly regulated and controlled by an amorphous region.

The rigid skeleton of the benzene ring of the polyester causes the fiber to have hard hand feeling in the clothing field, the softness of the fiber is not as good as that of natural fiber, and the comfort is seriously influenced. Because polyester molecular chains are regularly arranged and lack necessary polar functional groups such as hydroxyl and flexible macromolecules, the polyester has poor hygroscopicity, is easy to generate stuffy feeling and static electricity, and accumulates dust; dyeing needs to be carried out at high temperature and high pressure, and a large amount of energy consumption is consumed. The polyester further development must overcome the above performance disadvantages, and for this reason, three main improvements have been made in the prior art:

(1) Coating and finishing by using a surface finishing agent: the moisture absorption and softness of the fiber or fabric are generally improved by coating the fiber or fabric with a hydrophilic finishing agent, but the modification effect mechanism is that the hydrophilicity and softness of the fiber or fabric are endowed by virtue of the property of the coating finishing agent, the bonding force between the finishing agent and the fiber is poor, a temporary effect is generally achieved, and the moisture absorption effect is obviously reduced along with the increase of the use times and time.

(2) Blending, spinning and forming: the master batch with high hygroscopicity is used for blending and spinning to improve the hygroscopicity and the softness of the fiber, higher requirements are provided for the hygroscopicity and the stability of the master batch, and the blend can generate a phase separation phenomenon along with the increase of the mass fraction of the master batch, so that strict requirements are provided for a spinning process. Meanwhile, the master batch adding mode provides new requirements for production equipment, and a new device needs to be additionally purchased, so that the cost is greatly increased.

(3) And (3) copolymerization modification: the polyester fiber can be endowed with permanent hygroscopicity and softness performance, and in the prior copolymerization technology, the improvement of the softness and the hygroscopicity of the polyester fiber is generally realized by introducing polyol and polyethylene glycol macromolecules in polymerization. The polyester is obtained through esterification and polycondensation. But places severe demands on the stability of the polymerization process and the spinnability of the polyester.

Meanwhile, the existing polyester fiber hydrophilic antistatic performance improvement is mainly that certain hydrophilic components are introduced into the fiber surface or molecular chains by means of coating, blending or copolymerization methods, although the antistatic effect can be achieved through moisture absorption, effective moisture adsorption cannot be carried out when the external environment is in a low-humidity condition, the static phenomenon of the fiber cannot be improved, and the wearing comfort is affected.

There are also reports in the prior publications relating to the use of graphene or other carbon materials to modify polymers to achieve improved antistatic properties. Graphene has been widely used in various fields as a novel material by virtue of its excellent properties. However, when graphene is modified by introducing polyester, the following problems arise: firstly, the addition amount of graphene in the polymer is high, which causes the obvious increase of the cost, and secondly, the spinnability of the modified polyester with high addition amount of graphene is obviously reduced in the melt spinning process; and thirdly, the modified polyester fiber is hard in hand feeling due to the addition of the graphene, and the comfort of the fiber is poor.

Therefore, how to prepare a polyester fiber which has moisture absorption performance, quick drying performance, softness and good antistatic performance and can maintain excellent mechanical properties of the polyester fiber is a problem to be solved in the field.

Disclosure of Invention

The invention aims to overcome the defects that in the prior art, polyester fiber has good flexibility but poor antistatic performance and poor spinnability under a low humidity condition, or has good antistatic performance but large modified substance consumption, poor spinnability, poor fiber comfort and the like, and provides modified polyester, a preparation method thereof and application thereof as a summer quilt fabric. The modified polyester prepared by the invention has small surface contact angle and good moisture absorption performance; the polyester fiber prepared from the modified polyester has the advantages of moisture absorption performance, quick drying performance, softness and good antistatic performance, and can maintain excellent mechanical properties of the polyester fiber and excellent comprehensive performance.

According to the invention, the inventor introduces polyethylene glycol, a flaky conductive material and a rodlike conductive material to modify polyester at a molecular level from material design, and utilizes a flexible hydrophilic macromolecular chain and the conductive material to modify the polyester in a synergistic manner, so that the moisture absorption performance and the antistatic performance of the polyester are obviously improved.

The invention provides a titanium-silicon-cobalt composite catalyst, which comprises the following components in parts by weight: 58 to 70 parts of a titanium-based catalyst, 7 to 13 parts of a silicon-based catalyst, and 17 to 32 parts of a cobalt-based catalyst;

The preparation method of the titanium-silicon-cobalt composite catalyst comprises the following steps:

and dissolving the titanium catalyst and the cobalt catalyst in the silicon catalyst dispersion liquid in sequence, and then carrying out hydrothermal reaction to obtain the catalyst.

In the present invention, the titanium-based catalyst may be a titanium-containing compound conventionally used in the art, preferably a titanium-containing ester and/or a titanium-containing acid, more preferably tetrabutyl titanate and/or metatitanic acid.

In the present invention, the silicon-based catalyst may be a compound containing silicon element, which is conventional in the art, preferably a silicon-containing oxide, and more preferably silica.

In the present invention, the cobalt-based catalyst may be a compound containing cobalt, which is generally used in the art, preferably an acid containing cobalt, and more preferably cobalt acetate.

In the present invention, the titanium-based catalyst is preferably 63 to 68 parts, for example 65 parts.

In the present invention, the silicon-based catalyst is preferably 10 to 13 parts, for example, 13 parts.

In the present invention, the cobalt-based catalyst is preferably 18 to 25 parts, for example, 22 parts.

In the present invention, preferably, the titanium-silicon-cobalt composite catalyst comprises the following components by weight: 65 parts of tetrabutyl titanate, 13 parts of silicon dioxide and 22 parts of cobalt acetate.

In the present invention, the content of the titanium-based catalyst is preferably 58 to 70 wt%, for example 63 to 68 wt%, and further for example 65 wt%, wherein the percentage refers to the weight percentage of the titanium-silicon-cobalt composite catalyst.

In the present invention, the content of the silicon-based catalyst is preferably 7 to 13 wt%, for example 10 to 13 wt%, and further for example 13 wt%, wherein the percentage refers to the weight percentage of the titanium-silicon-cobalt composite catalyst.

In the present invention, the content of the cobalt-based catalyst is preferably 17 to 32 wt%, for example 18 to 25 wt%, and further for example 22 wt%, wherein the percentage refers to the weight percentage of the titanium-silicon-cobalt composite catalyst.

In the invention, preferably, in the titanium-silicon-cobalt composite catalyst, the titanium-based catalyst, the silicon-based catalyst and the cobalt-based catalyst respectively account for 58-70 wt%, 7-13 wt% and 17-32 wt% of the titanium-silicon-cobalt composite catalyst; more preferably, the percentage is 65 wt%, 13 wt% and 22 wt% of the titanium-silicon-cobalt composite catalyst, and the percentage refers to the weight percentage in the titanium-silicon-cobalt composite catalyst.

In the present invention, wt% means weight percentage.

In the present invention, the silicon-based catalyst dispersion may be prepared by a method conventional in the art, for example, by dispersing the silicon-based dispersant in a dispersant.

Wherein the dispersant may be a dispersant conventional in the art, and generally refers to a solvent capable of dissolving or dispersing the titanium-based catalyst, the silicon-based catalyst, and the cobalt-based catalyst, such as one or more of ethylene glycol, propylene glycol, and butylene glycol.

The dispersant can be selected according to the raw material or solvent of the reaction system catalyzed by the titanium-silicon-cobalt composite catalyst, for example, when ethylene glycol is used as the reaction raw material in the reaction system, the dispersant can be ethylene glycol.

Wherein the dispersion may be carried out according to procedures and conditions conventional in the art, such as ultrasonic dispersion or agitated dispersion.

The time of ultrasonic dispersion can be 15-45 min.

In the present invention, the dissolution may be carried out according to the conventional operations and conditions in the art, such as ultrasonic dissolution or agitation dissolution.

The inventors have found through research that the hydrothermal reaction can be carried out when the color of the solution in the system changes from purple red to red gray, which means that the cobalt ions are subjected to coordination reaction.

In the present invention, the hydrothermal reaction may be carried out under conditions and methods which are conventional in the art, and the conditions for the hydrothermal reaction, for example, the boiling point of the dispersant, may be generally selected according to the nature of the dispersant in the silicon-based catalyst dispersion.

Wherein, the hydrothermal reaction is generally carried out in a reaction kettle.

Wherein, when the dispersing agent in the silicon catalyst dispersing liquid is glycol, the temperature of the hydrothermal reaction is preferably 300-350 ℃. When the dispersing agent in the silicon-based catalyst dispersion liquid is ethylene glycol, the pressure of the hydrothermal reaction is preferably 20 to 35 MPa. When the dispersing agent in the silicon-based catalyst dispersion liquid is ethylene glycol, the hydrothermal reaction time is preferably 8-16 h.

As known to those skilled in the art, after the hydrothermal reaction is finished, the product after the reaction can be subjected to centrifugation and drying according to the conventional operation in the field.

Wherein, the centrifugation treatment can be carried out according to the conventional operation and conditions in the field, and the lower layer precipitation product obtained after centrifugation is generally taken.

Wherein the drying treatment can be carried out according to the conventional operation and conditions in the field, and the drying temperature is preferably 50-70 ℃, such as 60 ℃; the drying time is preferably 24-72 h, such as 48 h.

The titanium-silicon-cobalt composite catalyst has high-efficiency long-time catalytic performance, can be well dispersed in a polyester polymerization matrix, and can be used for preparing polyester with high intrinsic viscosity, low molecular weight distribution coefficient and high melting point, and the polyester with uniform performance can be prepared.

In the invention, when the titanium catalyst and the cobalt catalyst are simultaneously dissolved in the silicon catalyst dispersion liquid, the prepared titanium-silicon-cobalt composite catalyst has non-uniform catalytic performance, and the polyester prepared by catalysis has low intrinsic viscosity, high molecular weight distribution coefficient and low melting point.

In the invention, when the cobalt catalyst and the titanium catalyst are sequentially dissolved in the silicon catalyst dispersion liquid, the prepared titanium-silicon-cobalt composite catalyst has non-uniform catalytic performance, and the polyester prepared by catalysis has low intrinsic viscosity, high molecular weight distribution coefficient and low melting point.

The invention also provides an application of the titanium-silicon-cobalt composite catalyst as a polyester polycondensation reaction catalyst.

The invention also provides modified polyester which comprises the following raw materials: terephthalic acid, ethylene glycol, the titanium-silicon-cobalt composite catalyst and a modifying component;

the molar ratio of the titanium-silicon-cobalt composite catalyst to the ethylene glycol is (0.000005-0.002): 1;

the modified component comprises polyethylene glycol, a sheet conductive material and a rod-shaped conductive material, wherein the number average molecular weight of the polyethylene glycol is 400-6000 g/mol, and the mass ratio of the polyethylene glycol to the sheet conductive material is 1: (0.05-0.5), wherein the mass ratio of the polyethylene glycol to the rod-shaped conductive material is 1: (0.005-0.05);

The mass ratio of the modification component to the terephthalic acid is (0.005-0.2): 1.

in the present invention, the terephthalic acid and the ethylene glycol are main chains as a polyester, and the ratio of the terephthalic acid to the ethylene glycol may be a ratio conventional in the art, for example, the molar ratio of the terephthalic acid to the ethylene glycol is 1: (1.2-1.6), and further example is 1:1.26 or 1: 1.6.

In the present invention, the molar ratio of the titanium-silicon-cobalt composite catalyst to the ethylene glycol is preferably 0.00005: 1 or 0.002: 1.

In the present invention, the polyethylene glycol preferably has a relative number average molecular weight of 400g/mol, 1000g/mol, 2000g/mol or 6000 g/mol.

In the present invention, the sheet-like conductive material generally refers to a conductive material with a sheet-like shape, for example, the length, width and height of the sheet-like conductive material are x, y and z, respectively, where x and y are both greater than 10nm, z is 10-300 nm, and x: z is (10-20) 1, y: z is (10-30) 1.

Preferably, the flake conductive material is one or more of flake silver powder, flake gold powder and graphene, and further, the flake silver powder, the flake gold powder or the graphene is used as the flake conductive material.

The graphene is formed by sp from carbon atoms²The hybrid orbit forms a hexagonal honeycomb lattice two-dimensional carbon nano material which is generally sheet-shaped. The thickness of the graphene can be 1-3 layers. The thickness of the graphene is preferably 100-300 nm. The ratio of the length to the height of the graphene is preferably (10-20): 1. The width-to-height ratio of the graphene is preferably (10-30): 1.

In the invention, the rod-shaped conductive material generally refers to a conductive material with a rod-shaped appearance, for example, the outer diameter of the rod-shaped conductive material is 5-15 nm, and the length of the rod-shaped conductive material is 1-10 μm; further examples include one or more of silver rod powder, gold rod powder and carbon nanotube, and further examples include silver rod powder, gold rod powder and carbon nanotube

The carbon nano tube is a one-dimensional quantum material with the radial dimension of nanometer magnitude and the axial dimension of micrometer magnitude. The outer diameter of the carbon nanotube can be the size in the field, preferably 5-15 nm, such as 5nm, 10nm or 15 nm. The length of the carbon nanotube can be conventional in the art, and is preferably 1-10 μm, such as 1 μm, 2 μm or 10 μm.

Preferably, the carbon nanotubes have a size of 5nm in outer diameter, 1 μm in length, 15nm in outer diameter, 10 μm in length, 10nm in outer diameter, 2 μm in length, or 15nm in outer diameter, 1 μm in length.

In the invention, when the flake conductive material and the rod conductive material are used as the modified component of the modified polyester, the macroscopic state of the flake conductive material and the rod conductive material can be powder, such as flake silver powder, and the particle size of the powder can be 0.01-0.5 μm and can also be 1-2.5 μm.

In the present invention, the mass ratio of the polyethylene glycol to the sheet-like conductive material is preferably 1:0.05 or 1: 0.5.

In the present invention, the mass ratio of the polyethylene glycol to the rod-like conductive material is preferably 1 (0.01 to 0.05), for example, 1:0.01 or 1: 0.05.

When the sheet conductive material is graphene and the rod-like conductive material carbon nanotube, the mass ratio of the polyethylene glycol to the graphene is preferably 1:0.05 or 1:0.5, and the mass ratio of the polyethylene glycol to the carbon nanotube is preferably 1:0.005, 1:0.01 or 1: 0.05.

In the present invention, the mass ratio of the modifying component to the terephthalic acid is preferably (0.005 to 0.05): 1, e.g., 0.005:1, 0.025:1, or 0.05: 1.

In the present invention, the raw material of the modified polyester may further include a heat stabilizer and/or an antioxidant.

Wherein the heat stabilizer can be a heat stabilizer conventional in the art, preferably one or more of trimethyl phosphate, alkyl phosphate diester and tris (4-nonylphenyl) phosphite, such as trimethyl phosphate, alkyl phosphate dimethyl ester or tris (4-nonylphenyl) phosphite. The alkyl phosphodiester is preferably dimethyl methylphosphonate.

The amount of the heat stabilizer can be the amount conventionally used in the art, and preferably the amount of the heat stabilizer is 0.001 to 0.02% by mass, for example 0.01% or 0.0.2% by mass of the terephthalic acid.

When the heat stabilizer is trimethyl phosphate, the mass of the heat stabilizer is preferably 0.01% or 0.02% of the mass of the terephthalic acid.

When the heat stabilizer is dimethyl methyl phosphate, the mass of the heat stabilizer is preferably 0.02 percent of that of the terephthalic acid.

When the heat stabilizer is tris (4-nonylphenyl) phosphite, preferably the mass of the heat stabilizer is 0.02% of the mass of the terephthalic acid.

Wherein the antioxidant may be an antioxidant as is conventional in the art, preferably one or more of antioxidant 1010, antioxidant 168, and antioxidant 616, such as antioxidant 1010, antioxidant 168, or antioxidant 616.

The antioxidant can be used in an amount conventional in the art, and preferably, the amount of the antioxidant is 0.001 to 0.03% by mass, for example, 0.001%, 0.02% or 0.03% by mass, of the terephthalic acid.

When the antioxidant is antioxidant 168, preferably the mass of the antioxidant is 0.001% of the mass of the terephthalic acid.

When the antioxidant is antioxidant 616, preferably the mass of the antioxidant is 0.02% of the mass of the terephthalic acid.

When the antioxidant is antioxidant 1010, preferably the mass of the antioxidant is 0.03% of the mass of the terephthalic acid.

The invention also provides a preparation method of the modified polyester, which comprises the following steps:

(1) carrying out esterification reaction on the terephthalic acid and the ethylene glycol to obtain an esterification product;

(2) mixing the esterification product and the esterification additive in the step (1) in the presence of the titanium-silicon-cobalt composite catalyst, and carrying out polycondensation reaction to obtain modified polyester;

the esterification additive is a dispersion liquid containing the sheet-like conductive material, the rod-like conductive material and the polyethylene glycol.

In the step (1), preferably, the terephthalic acid and the ethylene glycol are subjected to pretreatment. The pretreatment may be a pulping treatment. The pulping treatment may be a pulping treatment in the art, for example, the terephthalic acid and the ethylene glycol are mixed, heated and stirred to become a slurry.

In the step (1), the reaction conditions of the esterification reaction may be those conventional in the art. The pressure of the esterification reaction is preferably 0.01-0.5 MPa. The temperature of the esterification reaction is preferably 230-260 ℃, for example 230 ℃ or 260 ℃. The esterification reaction time is preferably 2 to 4 hours, such as 2 hours or 4 hours.

In the step (1), when the water yield of the esterification reaction reaches 95-98% of the theoretical water yield, the esterification reaction is considered to be complete.

In the step (1), preferably, the terephthalic acid and the ethylene glycol are subjected to an esterification reaction in the presence of the titanium-silicon-cobalt composite catalyst to obtain an esterification product.

In the art, the catalyst used in the conventional polyester esterification reaction is an antimony-based catalyst, and the titanium-silicon-cobalt composite catalyst of the present invention can be used in the esterification reaction of the present invention. Compared with the conventional antimony catalyst, the titanium-silicon-cobalt composite catalyst has the following remarkable advantages:

one is as follows: the conventional antimony catalyst is heavy metal, and is easy to escape into a water environment when being applied to fiber weaving, dyeing and finishing, so that the ecological environment is greatly influenced, and the titanium-silicon-cobalt composite catalyst does not contain heavy metal components harmful to human bodies and has the characteristic of an ecological catalyst;

the second step is as follows: the titanium-silicon-cobalt composite catalyst has a catalytic effect on both the esterification reaction in the step (1) and the polycondensation reaction in the step (3), and compared with an antimony catalyst, the esterification reaction temperature and the reaction time in the step (1) are reduced, so that the energy is saved and the consumption is reduced.

When the raw materials of the modified polyester further comprise a heat stabilizer and/or an antioxidant, preferably, in the step (1), the terephthalic acid, the ethylene glycol and the heat stabilizer and/or the antioxidant are mixed, and an esterification product is obtained through an esterification reaction.

In the step (2), the esterification additive may be prepared by a conventional method in the art, for example, by dispersing the sheet-shaped conductive material and the rod-shaped conductive material in the polyethylene glycol.

Wherein the conditions for the dispersion may be those conventional in the art. Preferably, the dispersion is carried out under ultrasonic, beating conditions.

The temperature of the dispersion is preferably 70 to 90 ℃, for example 80 ℃.

The power of the ultrasound may be 0.15 kW.

The pulping may be a pulping treatment in the art, for example, the polyethylene glycol, the sheet-like conductive material, and the rod-like conductive material are mixed, heated, and stirred to become a slurry. The stirring time may be 24 h. The stirring speed can be 8000-10000 r/min. The stirring blade is preferably of boat type.

In the present invention, the inventors found that, when the conductive material is graphene and carbon nanotubes, the ether bond structure in the polyethylene glycol interacts with the hydroxyl groups in the graphene and carbon nanotubes to obtain inorganic nanopowder of the rivet through van der waals force, so that the conductive material can be more uniformly dispersed in the matrix.

In the invention, if the modified components are not uniformly dispersed, the modified components directly enter the polycondensation reaction after the esterification reaction is finished, and the system directly enters a vacuum negative pressure state, so that the polyethylene glycol is very easy to extract, and the polyethylene glycol enters a vacuum pipeline to be cooled after being extracted to block a device, thereby causing immeasurable harm to production.

In the step (2), the reaction conditions of the polycondensation reaction may be those conventional in the art. The pressure of the polycondensation reaction is preferably 10 to 100Pa (for example, 10Pa or 100Pa), and the time required for reducing the pressure from normal pressure to the reaction pressure may be 15 to 60 min. The temperature of the polycondensation reaction is preferably 260-280 ℃. The time of the polycondensation reaction is preferably 2-4 h.

As known to those skilled in the art, the atmospheric pressure is a standard atmospheric pressure, i.e., 0.1 MPa.

The invention also provides the modified polyester prepared by the preparation method.

In the present invention, the modified polyester has an intrinsic viscosity of 0.6 to 0.90dL/g, for example, 0.67dL/g, 0.68dL/g, 0.7dL/g or 0.85 dL/g.

In the invention, the molecular weight distribution coefficient PDI of the modified polyester is 1.10-1.25, such as 1.12, 1.15, 1.21 or 1.22.

In the invention, the melting point of the modified polyester is 245-255 ℃, such as 248 ℃, 249 ℃, 250 ℃ or 252 ℃.

In the present invention, the contact angle of the modified polyester is a surface contact angle of 45 ° to 50 °, for example, 45 °, 48 ° or 50 °.

The invention also provides a preparation method of the modified polyester fiber, which is obtained by melting and spinning the modified polyester.

Preferably, in the preparation method of the modified polyester fiber, the modified polyester is cut into particles and dried to obtain modified polyester chips, and the modified polyester chips are melt-spun through a profile spinneret plate, so as to obtain the modified polyester fiber.

The special-shaped spinneret plate can be a trilobal spinneret plate, a hollow spinneret plate, a cross spinneret plate, a Y-shaped or 8-shaped spinneret plate.

Preferably, the spinning process comprises:

the method comprises the following steps:

the spinning temperature is 270-300 ℃, the spinning speed is 800-1500 m/min, the stretching temperature is 60-80 ℃, the pre-stretching multiplying power is 1.02-1.10, the primary stretching multiplying power is 2.80-3.20, and the secondary stretching multiplying power is 1.05-1.15;

the second method comprises the following steps:

the spinning temperature is 270-300 ℃, the spinning speed is 2000-3000 m/min, the stretching temperature is 60-80 ℃, and the total stretching ratio is 1.5-5;

the third method comprises the following steps:

balancing the modified polyester fiber prepared in the second method, and then respectively winding and forming the modified polyester fiber by a first roller, a first hot box, a cooling plate, a PU disc false twister, a second roller, a network nozzle, a second hot box, a third roller and an oil wheel through a winding roller; the linear velocity of the first roller is 200-600 m/min, the linear velocity of the second roller is 500-600 m/min, the linear velocity of the third roller is 300-600 m/min, the linear velocity of the winding roller is 400-700 m/min, the draft ratio is 1.1-1.8, and the D/Y ratio of the PU disc false twister is 1.2-2.5; the time of the equilibration is preferably 8 hours;

The method four comprises the following steps:

the spinning temperature is 275-300 ℃, the spinning speed is 3500-4200 m/min, the speed of a hot roller GR1 is 1100-1500 m/min, the temperature is 80-110 ℃, the speed of a hot roller GR2 is 3550-4280 m/min, and the temperature is 115-135 ℃.

The invention also provides the modified polyester fiber prepared by the method.

When the spinning process is method one, the modified polyester fiber is prepared and then cut off to obtain the modified polyester staple fiber. The titer of the modified polyester staple fiber can be 0.3-5 dtex. The length of the modified polyester staple fiber may be 38mm or 51 mm.

When the spinning process is the second method, the prepared modified polyester fiber is pre-oriented yarn (high-speed spinning) (POY).

When the spinning process is the third method, the prepared modified polyester fiber is Draw Textured Yarn (DTY).

When the spinning process is the method four, the prepared modified polyester fiber is fully drawn yarn (spinning and drawing one-step process) (FDY).

In the invention, the titer of the modified polyester fiber is 0.3-5 dtex, such as 0.3dtex, 0.5dtex, 1.0dtex, 2.0dtex, 3.0dtex or 5.0dtex, and the modified polyester fiber has good dress application and processing performance.

In the invention, the fiber strength of the modified polyester fiber is 3.0-3.5 cN/dtex, such as 3.0cN/dtex, 3.1cN/dtex or 3.2cN/dtex, and the modified polyester fiber has good flexibility.

In the invention, the moisture regain of the modified polyester fiber is more than or equal to 1.0 percent, such as 1.2 percent, 1.3 percent or 1.65 percent, and the modified polyester fiber has good moisture absorption.

In the present invention, the modified polyester fiber has a fiber volume specific resistance (Ω. cm) of 10⁶～10⁸Ω. cm, e.g. 10⁶Ω.cm、10⁷Omega. cm or 10⁸Omega cm, has good antistatic performance.

The invention also provides application of the modified polyester fiber as a fabric, such as a summer quilt fabric.

Wherein the textile raw material may be a fiber conventionally understood in the art for spinning. Generally, the fabric stock may be crossed, knotted, joined, etc. to form a flat film mass, i.e., a fabric.

In the invention, the fabric made of the modified polyester fiber as the fabric raw material can be underwear, sports wear, linings and other fabrics with similar performance requirements as summer quilts.

On the basis of the common knowledge in the field, the above preferred conditions can be combined randomly to obtain the preferred embodiments of the invention.

The reagents and starting materials used in the present invention are commercially available.

The positive progress effects of the invention are as follows:

(1) compared with the traditional antimony catalyst, the titanium-silicon-cobalt composite catalyst introduced in the esterification reaction does not contain heavy metal components harmful to human bodies, especially meets the requirement of the antimony-free catalyst advocated by the state at present, and has the characteristic of an ecological catalyst. The titanium-silicon-cobalt composite catalyst can play a catalytic effect on both esterification reaction and polycondensation reaction, so that the esterification reaction temperature and the reaction time are reduced compared with antimony, and the energy is saved and the consumption is reduced.

(2) In the invention, functional components such as hydrophilic macromolecular chains, flaky conductive materials, rod-shaped conductive materials and the like are introduced, and the components have a synergistic modification effect; compared with the method of independently adding the sheet conductive material or the rod-shaped conductive material, the addition amount of the sheet conductive material and the rod-shaped conductive material is obviously reduced, the good antistatic performance can be still kept, and the spinnability of the modified polyester is ensured; the introduced hydrophilic flexible macromolecular chains can have a good dispersing effect on the flaky conductive material and the rodlike conductive material, so that the problems of agglomeration and the like of the conductive material with a micro-nano size due to high specific surface area are avoided, and the spinnability of the modified polyester is further improved; by the intercalation secondary action of the rodlike flaky conductive material in the amorphous region of the polyester and the moisture-conducting and moisture-permeable structure of hydrophilic molecules, the antistatic and hydrophilic properties of the material are improved, and the excellent effect is achieved under the condition of low addition amount.

(3) Compared with the conventional polyester reaction, after the esterification reaction is finished, the method directly enters the polycondensation reaction after the esterification reaction is finished, and performs the normal pressure reaction, so that the introduced modified components can be fully and uniformly mixed in the system in the normal pressure reaction process, and the phenomenon that the introduced modified components are pumped out and enter a vacuum pipeline for cooling to block a device, thereby causing the inestimable harm to the production is avoided.

(4) The hydrophilic antistatic polyester is formed by melt spinning through a profiled spinneret plate, the cross section of the prepared fiber is of a profiled structure, and the moisture-conducting performance is improved, so that a moisture absorption-moisture-conducting system is formed to maintain the optimal comfort level of human skin, and the comfort level of the polyester fiber is further enhanced. The fiber strength of the polyester fiber prepared by the invention is 3.0-3.5 cN/dtex, and the polyester fiber has good flexibility; the moisture regain is more than or equal to 1.0 percent, the water absorption is more than or equal to 200 percent, and the moisture absorption is good; the specific resistance (omega. cm) of the fiber is 10⁶～10⁸Omega.cm, has good antistatic performance; can be used for underwear, sports clothes and linings.

Drawings

FIG. 1 is a scanning electron microscope chromatogram of the titanium-silicon-cobalt composite catalyst of example 1, wherein the scale shows that 1 μm is divided into 10 equal parts.

Fig. 2 is an XRD spectrum of the titanium-silicon-cobalt composite catalyst of example 1.

FIG. 3 is an FTIR chart of the modified polyester chip of example 1.

FIG. 4 shows modified polyester chips obtained in example 1¹H-NMR chart.

Detailed Description

The invention is further illustrated by the following examples, which are not intended to limit the scope of the invention. The experimental methods without specifying specific conditions in the following examples were selected according to the conventional methods and conditions, or according to the commercial instructions.

In the following comparative examples of the agents, graphene was obtained from Heizhou sixth element New Material Co., Ltd, polyethylene glycol, tetrabutyl titanate, silica, cobalt acetate, and antimony trioxide were obtained from national pharmaceutical chemicals Co., Ltd, carbon nanotubes were obtained from Jiangsu Xifeng nanotechnology Co., Ltd, terephthalic acid and ethylene glycol were obtained from China petrochemical chemical instrumentation chemical fiber Co., Ltd, carboxyethyl cellulose was obtained from Arlatin reagent, and the other reagents were obtained from national pharmaceutical chemicals Co., Ltd.

In the following examples, the preparation method of the titanium-silicon-cobalt composite catalyst is as follows:

respectively taking 13 parts of silicon dioxide, 65 parts of tetrabutyl titanate and 22 parts of cobalt acetate, adding the silicon dioxide into an ethylene glycol dispersant according to the proportion for ultrasonic dispersion for 15-45 min, then adding the tetrabutyl titanate for dispersion for 30min, adding the cobalt acetate after the tetrabutyl titanate is dissolved, transferring the solution into a high-pressure hydrothermal synthesis reaction kettle after the color of the solution is changed from purple red to red gray, and adopting a high-temperature high-pressure hydrothermal reaction, wherein the high-temperature high-pressure hydrothermal reaction temperature is controlled to be 300-350 ℃, the high-temperature high-pressure hydrothermal reaction pressure is 20-35 MPa, and the hydrothermal reaction time is 8-16 h. After the high-temperature high-pressure hydrothermal reaction, obtaining a lower-layer precipitated product by adopting a centrifugal separation method, cleaning the filtered product by adopting clear water for 3 times, and then drying in vacuum at 60 ℃ for 48 hours to obtain the titanium-silicon-cobalt composite catalyst.

The titanium-silicon-cobalt composite catalyst prepared by the preparation method can be seen in figures 1 and 2.

FIG. 1 is a scanning electron microscope atlas of the prepared titanium-silicon-cobalt composite catalyst, and as can be seen from FIG. 1, the particle size of the composite catalyst is 150-200 nm;

FIG. 2 is an XRD pattern of the composite catalyst, which is obtained by analyzing, (a) a crystal diffraction characteristic pattern of the cobalt-based catalyst, (b) a crystal characteristic diffraction pattern of the titanium-based catalyst, (c) a crystal characteristic diffraction pattern of the silicon-based catalyst, and (d) a crystal characteristic diffraction pattern of the titanium-silicon-cobalt composite catalyst; the superposition of diffraction peaks of three catalysts appears near 27.5 degrees, so that the characteristic diffraction peak is strengthened, a new diffraction peak is formed when 38.2 degrees of a titanium catalyst and 35.1 degrees of a cobalt catalyst are close to each other near 37.0 degrees, the peak shape is widened, the diffraction peaks of 43.4 degrees of the cobalt catalyst and 48.5 degrees of the titanium catalyst disappear, a new characteristic peak of 51.6 degrees appears in an XRD (X-ray diffraction) pattern of the titanium-cobalt-silicon composite catalyst, and the characteristic peaks of other cobalt catalysts and other titanium catalysts appear in the composite catalyst pattern, so that catalytic components in the catalysts are reserved in the composite catalyst.

Example 1

(1) Mixing terephthalic acid and ethylene glycol according to a molar ratio of 1:1.26 in the presence of a titanium-silicon-cobalt composite catalyst, wherein the molar ratio of the titanium-silicon-cobalt composite catalyst to the ethylene glycol is 0.000005: 1; simultaneously adding a trimethyl phosphate heat stabilizer and an antioxidant 168, and uniformly mixing, wherein the mass of the heat stabilizer is 0.01% of that of the terephthalic acid, and the mass of the antioxidant is 0.001% of that of the terephthalic acid;

carrying out an esterification reaction: the reaction pressure is 0.01-0.05 MPa, the reaction temperature is 230 ℃, and the reaction time is 4 hours, so as to obtain an esterification product;

(2) feeding polyethylene glycol (with the number average molecular weight of 400g/mol), graphene (with the thickness of 100-300 nanometers and the length-height ratio of (10-20): 1, and the width-height ratio of (10-30): 1) and carbon nano tubes (with the outer diameter of 5nm and the length of 1 mu m) according to the mass ratio of 1:0.05 to the polyethylene glycol to the graphene, the mass ratio of 1:0.005 to the polyethylene glycol to the carbon nano tubes and the mass ratio of 0.05:1 to terephthalic acid;

according to the proportion, carrying out ultrasonic high-speed pulping and dispersion on polyethylene glycol, graphene and carbon nano tubes at 80 ℃, wherein the pulping time is 24h, the stirring speed is 8000-10000 r/min during the ultrasonic high-speed pulping and dispersion in the pulping process, the paddle is selected to be a ship shape in the ultrasonic high-speed pulping process, and the ultrasonic dispersion has the dispersion power of 0.15 kW; pulping and dispersing to obtain an esterification additive;

(3) And (2) mixing the esterification product in the step (1) and the esterification additive in the step (2) in the presence of a titanium-silicon-cobalt composite catalyst, and reacting for 2-4 hours at the temperature of 260-280 ℃ under the pressure of 100Pa (60 min for reducing the pressure from normal pressure to reaction pressure). And after the reaction is finished, discharging and granulating to obtain the modified polyester chip.

An FTIR chart of the modified polyester chip obtained in this example is shown in FIG. 3. As can be seen from FIG. 3, 3000cm^-1Hereinafter, 2965cm^-1Is a characteristic absorption peak of hydrogen on ethyl in polyester, 1715cm^-1Is the characteristic absorption peak of C ═ O in polyester, 1578cm^-1、1409cm^-1、1341cm^-1Corresponding to the characteristic absorption peak of benzene ring in polyester, 1248cm^-1Corresponding to the characteristic absorption peak of the C-O bond on the polyethylene glycol as the modifying component, and simultaneously 1100cm^-1And 1018cm^-1The characteristic absorption peaks of C-O in the polyester and polyethylene glycol in the molecular structure can be known by infrared spectrum analysis, and the polyethylene glycol modified polyester is obtained by the implementation.

Modified polyester chips obtained in this example¹FIG. 4 is a H-NMR chart. As can be seen from FIG. 4, 8.2ppm corresponds to the characteristic absorption peak of hydrogen atom on benzene ring, 4.9ppm corresponds to the characteristic absorption peak of hydrogen atom on ethyl group in ethylene glycol, 4.84ppm and 4.37ppm correspond to the characteristic absorption peaks of modified component polyethylene glycol, and diethylene glycol structure formed during polyester polymerization is also detected in 3.93ppm, and the analysis of nuclear magnetic spectrum also confirms that polyethylene glycol modified polyester is prepared in this example.

Example 2

(1) Mixing terephthalic acid and ethylene glycol according to a molar ratio of 1:1.6 in the presence of a titanium-silicon-cobalt composite catalyst, wherein the molar ratio of the titanium-silicon-cobalt composite catalyst to the ethylene glycol is 0.002: 1; simultaneously adding a dimethyl methyl phosphate heat stabilizer and an antioxidant 616, and uniformly mixing, wherein the mass of the heat stabilizer is 0.02 percent of that of the terephthalic acid, and the mass of the antioxidant is 0.02 percent of that of the terephthalic acid;

then carrying out esterification reaction: the reaction pressure is 0.01-0.05 MPa, the reaction temperature is 260 ℃, and the reaction time is 2 hours, so that the esterification product is obtained.

(2) Selecting polyethylene glycol (with the number average molecular weight of 6000g/mol), graphene (with the thickness of 100-300 nanometers and the thickness of 1-3 layers, the length-height ratio of (10-20): 1, the width-height ratio of (10-30): 1) and carbon nano tubes (with the outer diameter of 15nm and the length of 10 mu m); feeding according to the mass ratio of 1:0.5 of polyethylene glycol to graphene, the mass ratio of 1:0.05 of polyethylene glycol to carbon nano tubes, and the mass ratio of the sum of the mass of polyethylene glycol, graphene and carbon nano tubes to terephthalic acid of 0.005: 1;

(3) And (3) mixing the esterification product in the step (1) and the esterification additive in the step (2) in the presence of a titanium-silicon-cobalt composite catalyst, and reacting for 2-4 hours at the temperature of 260-280 ℃ under the pressure of 10Pa (the time required for reducing the pressure from normal pressure to reaction pressure is 15 min). And after the reaction is finished, discharging and granulating to obtain the modified polyester chip.

Example 3

(1) The dosage ratio of the terephthalic acid, the glycol and the titanium-silicon-cobalt composite catalyst is the same as that of the example 1; adding a tris (4-nonylphenyl) phosphite heat stabilizer and an antioxidant 1010 at the same time, and uniformly mixing, wherein the mass of the tris (4-nonylphenyl) phosphite is 0.02% of that of the terephthalic acid, and the mass of the antioxidant 1010 is 0.03% of that of the terephthalic acid;

(2) selecting polyethylene glycol (the number average molecular weight is 2000g/mol), graphene (the thickness is 100-300 nanometers, the length-height ratio is (10-20): 1, the width-height ratio is (10-30): 1) and carbon nanotubes (the outer diameter is 10nm, and the length is 2 mu m);

feeding according to the mass ratio of 1:0.05 of polyethylene glycol to graphene, 1:0.01 of polyethylene glycol to carbon nano tubes and 0.025:1 of terephthalic acid to the sum of the mass of polyethylene glycol, graphene and carbon nano tubes;

According to the proportion, carrying out ultrasonic high-speed pulping and dispersion on polyethylene glycol, graphene and carbon nano tubes at the temperature of 80 ℃, wherein the pulping and dispersion conditions are the same as those of example 1, so as to obtain an esterification additive;

(3) the same as in example 1.

Example 4

(1) The dosage ratio of the terephthalic acid, the glycol and the titanium-silicon-cobalt composite catalyst is the same as that of the example 2; simultaneously adding a trimethyl phosphate heat stabilizer and an antioxidant 616, and uniformly mixing, wherein the mass of trimethyl phosphate is 0.02 percent of the mass of the terephthalic acid, and the mass of the antioxidant 616 is 0.02 percent of the mass of the terephthalic acid;

(2) feeding polyethylene glycol (with the number average molecular weight of 1000g/mol), graphene (with the thickness of 100-300 nanometers and the length-height ratio of (10-20): 1, and the width-height ratio of (10-30): 1) and carbon nanotubes (with the outer diameter of 15nm and the length of 1 mu m) according to the mass ratio of 1:0.05 to the polyethylene glycol to the graphene, the mass ratio of 1:0.005 to the polyethylene glycol to the carbon nanotubes, and the mass ratio of the sum of the mass of the polyethylene glycol, the graphene and the carbon nanotubes to terephthalic acid of 0.005: 1;

according to the proportion, carrying out ultrasonic high-speed pulping and dispersion on polyethylene glycol, graphene and carbon nano tubes at the temperature of 80 ℃, wherein the pulping and dispersion conditions are the same as those of the example 2, so as to obtain an esterification additive;

(3) The same as in example 2.

Comparative example 1

The titanium-silicon-cobalt composite catalyst species in step (1) and step (3) were replaced with antimony trioxide catalyst, and the remainder was the same as in example 1.

Comparative example 2

The raw material types of the esterification additives in the step (2) are polyethylene glycol and graphene, and the method is the same as example 1 except that carbon nanotubes are not contained.

Comparative example 3

The raw materials of the esterification additive in the step (2) are polyethylene glycol and carbon nanotubes, and graphene is not contained, as in example 1.

Comparative example 4

By adopting a melt blending method, the conventional bright polyester chip (with the intrinsic viscosity of 0.675dL/g, PDI of 1.21 and melting point of 250 ℃) is used as a raw material, graphene and carbon nano tubes are used as an addition modifier, and the polyester chip is prepared by melt blending at 275 ℃, wherein the addition amount of the graphene and the carbon nano tubes is the same as that of the polyester chip in example 1.

Comparative example 5

The raw materials of the esterification additive in the step (2) are carboxyethyl cellulose, graphene and carbon nano tubes, and the materials are fed according to the mass ratio of 1:0.05 to the carboxyethyl cellulose to the graphene, the mass ratio of 1:0.005 to the carboxyethyl cellulose to the carbon nano tubes and the mass ratio of 0.05:1 to the terephthalic acid;

The rest is the same as example 1.

Comparative example 6

The raw materials of the esterification additive in the step (2) are Tween-20, graphene and carbon nano tubes, and the materials are fed according to the mass ratio of the Tween-20 to the graphene of 1:0.05, the mass ratio of the Tween-20 to the carbon nano tubes of 1:0.005 and the mass ratio of the sum of the Tween-20, the graphene and the carbon nano tubes to the terephthalic acid of 0.05: 1;

the rest is the same as example 1.

Comparative example 7

In step (2), polyethylene glycol (number average molecular weight 200g/mol) graphene (thickness 100-300 nm, 1-3 layers) and carbon nanotubes (outer diameter 5nm, length 1 μm) are taken to prepare an esterification additive, and the rest is the same as in example 1.

Comparative example 8

In the step (2), polyethylene glycol (with a number average molecular weight of 8000g/mol), graphene (with a thickness of 100-300 nm and 1-3 layers) and carbon nanotubes (with an outer diameter of 5nm and a length of 1 μm) are taken to prepare an esterification additive, and the rest is the same as in example 1.

Comparative example 9

The titanium-silicon-cobalt composite catalyst in the step (1) and the step (3) is a catalytic system prepared by simultaneously dissolving tetrabutyl titanate and cobalt acetate in a silicon dioxide dispersion liquid, and the preparation process is the same as that of the titanium-silicon-cobalt composite catalyst.

The modified polyester was prepared as in example 1.

Comparative example 10

The titanium-silicon-cobalt composite catalyst in the step (1) and the step (3) is a catalytic system prepared by sequentially dissolving cobalt acetate and tetrabutyl titanate in a silicon dioxide dispersion liquid, and the preparation process is the same as that of the titanium-silicon-cobalt composite catalyst.

The modified polyester was prepared as in example 1.

Example 5

Taking the modified polyester prepared in the example 1, modified polyester fiber is prepared under the following process conditions: the spinning temperature is 270-300 ℃, the spinning speed is 800-1500 m/min, the stretching temperature is 60-80 ℃, the pre-stretching multiplying power is 1.02-1.10, the primary stretching multiplying power is 2.80-3.20, and the secondary stretching multiplying power is 1.05-1.15; and cutting the modified polyester fiber to obtain the modified polyester staple fiber. The fineness of the modified polyester staple fiber was 33dtex, and the length of the modified polyester staple fiber was 44 mm.

Example 6

The modified polyester prepared in example 2 was used to prepare a modified pre-oriented polyester fiber under the following melt spinning process conditions: the modified pre-oriented polyester fiber is prepared by adopting cross-shaped spinneret orifices, wherein the melt spinning temperature is 270-300 ℃, the spinning speed is 2000-3000 m/min, the drawing temperature is 60-80 ℃, and the total drawing ratio is 1.5-5.

Example 7

Taking the modified polyester prepared in the embodiment 3, wherein a spinneret orifice is in an 8-shaped structure, and the modified pre-oriented polyester fiber prepared by the method in the embodiment 6 is balanced and then respectively passes through a first roller, a first hot box, a cooling plate, a PU disc false twister, a second roller, a network nozzle, a second hot box, a third roller and an oil tanker, and finally is wound and formed through a winding roller; wherein the linear velocity of the first roller is 200-600 m/min, the linear velocity of the second roller is 500-600 m/min, the linear velocity of the third roller is 300-600 m/min, the linear velocity of the winding roller is 400-700 m/min, the draft ratio is 1.1-1.8, and the D/Y ratio of the PU disc false twister is 1.2-2.5; the time of the equilibration is preferably 8 hours; and preparing the modified polyester DTY fiber.

Example 8

The modified polyester prepared in the example 4 is taken, and is spun by a hollow spinneret at 275-300 ℃ and 3500-4200 m/min, a hot roller GR1 at 1100-1500 m/min and 80-110 ℃ and a hot roller GR2 at 3550-4280 m/min and 115-135 ℃ to prepare Fully Drawn Yarn (FDY).

Comparative example 11

The modified polyester fiber was prepared by taking the modified polyester obtained in comparative example 1 and referring to the spinning process and method of example 5.

Comparative example 12

The modified polyester fiber was prepared by taking the modified polyester obtained in comparative example 2 and referring to the spinning process and method of example 6.

Comparative example 13

The modified polyester fiber was prepared by taking the modified polyester obtained in comparative example 3 and referring to the spinning process and method of example 7.

Comparative example 14

The modified polyester fiber was prepared by taking the modified polyester obtained in comparative example 4 and referring to the spinning process and method of example 8.

Effects of the embodiment

The modified polyesters prepared in the above examples 1 to 8 and comparative examples 1 to 14 were subjected to the following performance tests, the test items being as follows:

the relative viscosity of the section is tested by an SC-1632Z full-automatic intrinsic viscosity tester produced by Changshisanshen instrument science and technology Limited according to the test method in GB/T10247-2008.

The melting point was measured by using an X6 series micro melting point measuring instrument manufactured by Beijing century Kexin scientific instruments Co., Ltd according to the test method in FZ/T51004-2011.

The molecular weight distribution coefficient of the slices was measured by using a model 1206 gel permeation chromatograph GPC produced by Agilent and carbon tetrachloride as a solvent.

The surface contact angle was measured by an automatic video contact angle meter of OCA40Micro model manufactured by Germany Dataphysics at 25 ℃ by a static contact angle method to measure the wettability of the polyester sample, and for the sliced sample, the sample was first injection molded into a master piece with a diameter of 25mm and a thickness of 3mm and a droplet size of 2.0. mu.L of deionized water.

The fineness of the fiber is tested by a YG086 type strand yarn length measuring machine of the first textile equipment of Changzhou city according to the test method in GB/T14343-2008 standard.

The strength of the fiber is tested by an XL-2 multifilament tensile tester produced by Shanghai Lipu applied science and technology research according to the test method in GB/T14344-2008 standard.

The fiber moisture regain is tested by adopting a Changzhou instrument YG747 type fast eight blue constant temperature oven according to a national standard GB/T6503-once 2008 method.

The fiber volume specific resistance adopts a GB/T14342-2015 method and a YG321 type fiber specific resistance instrument manufactured by Nantong Sansi electromechanical technology limited.

The infrared spectrum of the sample was measured by means of an Attenuated Total Reflectance (ATR) method using a Nicolet 6700 Fourier transform infrared spectrometer manufactured by Thermo Fisher, USA.

The NMR spectrum was obtained by using an Avance 400 NMR spectrometer manufactured by Bruker, Switzerland, and the sample was tested using trifluoroacetic acid as a solvent.

The scanning static electricity of the sample is tested by using an SU 8010 field emission electron scanning microscope at Hitachi, the sample is sprayed with gold firstly in the testing process, and the voltage is 5kv in the testing process.

XRD result analysis of the sample, the unit cell parameters of the catalyst were measured by D/max-2550PC X-ray polycrystal diffractometer (XRD) manufactured by Rigaku corporation of Japan, and retrieved by a standard card to obtain corresponding XRD diffraction data.

TABLE 1

From the data in table 1, it can be seen that:

(1) the titanium-silicon-cobalt composite catalyst adopted in the embodiments 1 to 4 has excellent catalytic effect, has very excellent catalytic performance when the addition amount is extremely low, and can effectively regulate and control the molecular weight of the modified polyester;

(2) The polyester chips prepared in the embodiments 1 to 4 have good viscosity uniformity, good molecular weight uniformity, narrow distribution and good chip hydrophilicity;

(3) comparative examples 1 to 4 show that the type of the catalyst and the form of the conductive material are closely related to the molecular weight uniformity and hydrophilicity of the polyester molecules, when the type of the catalyst or the form of the conductive material is changed, the molecular weight distribution of the prepared polyester chip is wide, the hydrophilicity is poor, and the hydrophilicity is not obviously improved even if the same hydrophilic component and the same conductive material are added;

(4) comparative examples 5 to 6 show that in the preparation method of the present application, any kind of hydrophilic modification component is not suitable, and as shown in comparative examples 5 and 6, when carboxyethyl cellulose and tween-20 are used as the hydrophilic modification component, polymerization is not possible;

the inventor finds that common hydrophilic modification components/dispersants, such as carboxyethyl cellulose, tween-20 and the like, have a polyether bond structure in the molecular structure of the dispersant, and are acted by a composite catalyst in the polyester polymerization catalysis process, so that transitional crosslinking is caused, the polymerization reaction is seriously influenced, and finally, the continuous section is difficult to grow, and the system transition gel cannot be polymerized to obtain a product;

(5) Comparative examples 7 to 10 show that the molecular weight of the hydrophilic component and the preparation method of the catalyst are closely related to the molecular weight uniformity and hydrophilicity of the polyester molecule, and when the molecular weight of the hydrophilic component and the preparation method of the catalyst are changed, the prepared polyester chip has poor hydrophilicity, and even if the same hydrophilic component and the same conductive material are added, the hydrophilicity is not obviously improved;

the inventor of the invention has repeatedly studied and found that the polyethylene glycol in the modified polyester mainly provides a channel for water transmission, the polyethylene glycol is mainly distributed in an amorphous region of the polyester in the polymerization process, and the molecular weight of the polyethylene glycol is too large or too small, so that the distribution of the polyester molecular chain segments is not uniform (as shown in comparative example 8 and comparative example 9), and the hydrophilic performance of the modified polyester is seriously influenced.

TABLE 2

As can be seen from the data in table 2:

the polyester chips obtained in examples 1 to 4 were melt-spun to obtain fibers of examples 5 to 8, and the properties thereof were evaluated as follows:

(1) from examples 5 to 8, it is clear that the polyester fiber prepared in the present application has excellent spinnability, high fiber strength, and excellent hydrophilic and antistatic properties;

(2) the composite catalyst has excellent catalytic performance and has the effect of enhancing the hydrophilic and antistatic performance of the modified component;

As shown in comparative examples 11 and 14, the modified polyester fiber obtained by catalysis with other single component catalysts without using a composite catalyst has reduced fiber strength and poor hydrophilicity and antistatic property, and even if the modified components (polyethylene glycol, graphene and carbon nanotube) of the same kind and proportion as those of the present application are added, the performance is not effectively improved;

furthermore, as shown in comparative example 14, when the polyester chip prepared by adding graphene and carbon nanotubes in the ratio of example 1 of the present application was spun, the spinning performance was very poor, the fiber strength was very low, and it was almost difficult to form fibers.

Claims

1. The titanium-silicon-cobalt composite catalyst is characterized by comprising the following components in parts by weight: 58 to 70 parts of a titanium-based catalyst, 7 to 13 parts of a silicon-based catalyst, and 17 to 32 parts of a cobalt-based catalyst;

2. The titanium-silicon-cobalt composite catalyst according to claim 1, wherein the titanium-based catalyst is an ester containing a titanium element and/or an acid containing a titanium element, preferably tetrabutyl titanate and/or metatitanic acid;

And/or, the silicon-based catalyst is a silicon-containing oxide, preferably silicon dioxide;

and/or the cobalt catalyst is acid containing cobalt element, preferably cobalt acetate;

and/or 63-68 parts of titanium catalyst, preferably 65 parts;

and/or 10-13 parts of silicon catalyst, preferably 13 parts;

and/or 18-25 parts of cobalt catalyst, preferably 22 parts;

and/or, the silicon catalyst dispersion is prepared by dispersing the silicon dispersing agent in a dispersing agent; wherein, the dispersant is preferably one or more of ethylene glycol, propylene glycol and butanediol; the dispersion is preferably ultrasonic dispersion or stirring dispersion, and the ultrasonic dispersion time is preferably 15-45 min;

and/or the dissolving is ultrasonic dissolving or stirring dissolving;

and/or the hydrothermal reaction is carried out in a reaction kettle;

and/or when the dispersing agent in the silicon-based catalyst dispersion liquid is ethylene glycol, the temperature of the hydrothermal reaction is preferably 300-350 ℃, the pressure of the hydrothermal reaction is preferably 20-35 MPa, and the time of the hydrothermal reaction is preferably 8-16 h;

and/or after the hydrothermal reaction is finished, performing centrifugal treatment and drying treatment on a product after the reaction; the drying temperature is preferably 50-70 ℃, and the drying time is preferably 24-72 hours;

Or the content of the titanium catalyst is 58-70 wt%, preferably 63-68 wt%, more preferably 65 wt%, and the percentage refers to the weight percentage in the titanium-silicon-cobalt composite catalyst;

or the content of the silicon-based catalyst is 7-13 wt%, preferably 10-13 wt%, more preferably 13 wt%, and the percentage refers to the weight percentage in the titanium-silicon-cobalt composite catalyst;

or the content of the cobalt catalyst is 17-32 wt%, preferably 18-25 wt%, and more preferably 22 wt%, and the percentage refers to the weight percentage in the titanium-silicon-cobalt composite catalyst.

3. Use of a titanium silicon cobalt composite catalyst according to claim 1 or 2 as a polycondensation catalyst for polyester.

4. The modified polyester is characterized by comprising the following raw materials: terephthalic acid, ethylene glycol, titanium-silicon-cobalt composite catalyst and modified components;

the titanium-silicon-cobalt composite catalyst is as defined in any one of claims 1 to 3;

5. the modified polyester of claim 4, wherein the molar ratio of terephthalic acid to ethylene glycol is 1: (1.2-1.6), preferably 1:1.26 or 1: 1.6;

and/or the molar ratio of the titanium-silicon-cobalt composite catalyst to the ethylene glycol is 0.00005: 1 or 0.002: 1;

and/or the polyethylene glycol has a relative number average molecular weight of 400g/mol, 1000g/mol, 2000g/mol or 6000 g/mol;

and/or the length, the width and the height of the sheet-shaped conductive material are x, y and z respectively, wherein x and y are both larger than 10nm, z is 10-300 nm, and x: z is (10-20) 1, y: z is (10-30) 1; preferably, the flake conductive material is one or more of flake silver powder, flake gold powder and graphene, the thickness of the graphene is preferably 100-300 nm, the length-height ratio of the graphene is preferably (10-20): 1, and the width-height ratio of the graphene is preferably (10-30): 1;

and/or the outer diameter of the rod-shaped conductive material is 5-15 nm, and the length of the rod-shaped conductive material is 1-10 mu m; preferably, the flaky conductive material is one or more of rod-shaped silver powder, rod-shaped gold powder and a carbon nanotube, the outer diameter of the carbon nanotube is preferably 5-15 nm, and the length of the carbon nanotube is preferably 1-10 μm;

And/or the mass ratio of the polyethylene glycol to the flaky conductive material is 1:0.05 or 1: 0.5;

and/or the mass ratio of the polyethylene glycol to the rod-shaped conductive material is 1 (0.01-0.05), preferably 1:0.01 or 1: 0.05;

and/or the mass ratio of the modification component to the terephthalic acid is (0.005-0.05): 1, preferably 0.005:1, 0.025:1 or 0.05: 1;

and/or the raw materials of the modified polyester also comprise a heat stabilizer and/or an antioxidant; wherein the heat stabilizer is one or more of trimethyl phosphate, alkyl phosphate diester and tri (4-nonylphenyl) phosphite, more preferably trimethyl phosphate, alkyl phosphate dimethyl ester or tri (4-nonylphenyl) phosphite, and the alkyl phosphate diester is preferably methyl phosphate dimethyl ester; preferably, the mass of the heat stabilizer is 0.001-0.02% of that of the terephthalic acid; the antioxidant is preferably one or more of antioxidant 1010, antioxidant 168 and antioxidant 616; preferably, the mass of the antioxidant is 0.001-0.03% of the mass of the terephthalic acid.

6. A process for preparing a modified polyester according to claim 4 or 5, comprising the steps of:

7. The process for producing a modified polyester according to claim 6, wherein in the step (1), the terephthalic acid and the ethylene glycol are subjected to a pretreatment, preferably a beating treatment; preferably, the terephthalic acid and the ethylene glycol are mixed, heated and stirred to become slurry;

and/or in the step (1), the pressure of the esterification reaction is 0.01-0.5 MPa;

and/or in the step (1), the temperature of the esterification reaction is 230-260 ℃, preferably 230 ℃ or 260 ℃;

and/or in the step (1), the esterification reaction time is 2-4 h, preferably 2h or 4 h;

and/or, in the step (1), carrying out esterification reaction on the terephthalic acid and the ethylene glycol in the presence of the titanium-silicon-cobalt composite catalyst to obtain an esterification product;

And/or, in the step (1), when the raw material of the modified polyester further comprises a heat stabilizer and/or an antioxidant, mixing the terephthalic acid, the ethylene glycol and the heat stabilizer and/or the antioxidant, and carrying out esterification reaction to obtain an esterification product;

and/or, in the step (2), the esterification additive is prepared by dispersing the sheet conductive material and the rod conductive material in the polyethylene glycol; preferably, the dispersion is carried out under the conditions of ultrasound and beating; the temperature of the dispersion is preferably 70-90 ℃, and the power of the ultrasound is preferably 0.15 kW; the pulping is processed according to the following method, the polyethylene glycol, the flaky conductive material and the rodlike conductive material are mixed, heated and stirred to be in a pulp state, and then the product is obtained; the stirring time is preferably 24 hours, the stirring speed is preferably 8000-10000 r/min, and the stirring blade is preferably in a ship shape;

and/or in the step (2), the pressure of the polycondensation reaction is 10-100 Pa, preferably 10Pa or 100 Pa;

and/or in the step (2), the temperature of the polycondensation reaction is 260-280 ℃;

and/or in the step (2), the time of the polycondensation reaction is 2-4 h.

8. A modified polyester obtained by the process for producing a modified polyester as claimed in claim 6 or 7.

9. A method for preparing modified polyester fiber, which is characterized in that the modified polyester fiber is obtained by melting and spinning the modified polyester fiber according to any one of claims 4, 5 and 8; preferably, the modified polyester is cut into particles and dried to prepare modified polyester chips, and the modified polyester chips are melt-spun through a profile spinneret plate to obtain the modified polyester chip; the spinning process is preferably the first method, the second method, the third method or the fourth method:

the method comprises the following steps:

the second method comprises the following steps:

the third method comprises the following steps:

The method four comprises the following steps:

10. A modified polyester fiber obtained by the process for producing a modified polyester fiber according to claim 9.

11. Use of the modified polyester fiber according to claim 10 as a fabric, preferably a summer cover.