CN109680358B

CN109680358B - Polyester industrial yarn for aerial work safety belt and preparation method thereof

Info

Publication number: CN109680358B
Application number: CN201811614146.XA
Authority: CN
Inventors: 杨超明; 丁竹君; 汤方明
Original assignee: Jiangsu Hengli Chemical Fiber Co Ltd
Current assignee: Jiangsu Hengli Chemical Fiber Co Ltd
Priority date: 2018-12-27
Filing date: 2018-12-27
Publication date: 2020-10-16
Anticipated expiration: 2038-12-27
Also published as: CN109680358A

Abstract

The invention relates to a polyester industrial yarn for a safety belt for high-altitude operation and a preparation method thereof, wherein the polyester industrial yarn for the safety belt for high-altitude operation is prepared by carrying out solid-phase polycondensation tackifying, melting, metering, extruding, cooling, oiling, stretching, heat setting and winding on a modified polyester melt; the preparation method of the modified polyester before solid phase polycondensation tackifying comprises the following steps: uniformly mixing terephthalic acid, ethylene glycol, dihydric alcohol with trimethylsilyl lateral group, hexanediol with tert-butyl lateral group and zinc oxide powder, and then carrying out esterification reaction and polycondensation reaction in sequence, wherein the light fastness of the polyester industrial yarn for the aerial work safety belt is 7-8 grade, the ultraviolet transmittance is less than 5 percent, the dye uptake under the temperature condition of 130 ℃ is 88.4-93.7 percent, and the K/S value is 24.24-26.56. The method has simple process, and the prepared polyester industrial yarn has good dyeing property.

Description

Polyester industrial yarn for aerial work safety belt and preparation method thereof

Technical Field

The invention belongs to the technical field of modified polyester fibers, and relates to a polyester industrial yarn for a safety belt for aerial work and a preparation method thereof.

Background

Polyethylene terephthalate (PET) fibers have been developed rapidly since the advent due to their excellent properties, and their production has become the world's cap of synthetic fibers. The polyester fiber has a series of excellent performances such as high breaking strength, high elastic modulus, moderate resilience, excellent heat setting performance, good heat resistance, light resistance, acid resistance, alkali resistance, corrosion resistance and the like, and the fabric prepared from the polyester fiber has the advantages of good crease resistance, good stiffness and smoothness and the like, so the polyester fiber is widely applied to the fields of clothing, home textiles and the like.

The safety belt is a personal protection article for preventing falling accidents of workers working at high altitudes, consists of a belt, a rope and metal accessories, is generally called as the safety belt and is suitable for high altitude operation occasions such as surrounding poles, hanging, climbing and the like, the high-strength polyester industrial yarn is an excellent material for manufacturing the safety belt for high altitude operation, and the safety belt generally needs to be dyed so as to be convenient to distinguish.

However, since terylene is hydrophobic fiber, the molecules of terylene do not contain hydrophilic groups, and the molecular structure of terylene lacks active groups which can be combined with dye, such as cellulose or protein fiber, and ester groups on terylene fiber have the function of forming hydrogen bonds with disperse dye, but the molecular chain structure of terylene is compact, so that dye molecules are difficult to enter the interior of fiber. Therefore, only disperse dyes can be selected when dyeing terylene, and the dyeing performance of terylene fiber is not good. In addition, the finished product of the polyester fiber is a partially crystallized supermolecular structure, molecular chains of the crystallized parts of the polyester fiber are mutually parallel and mostly in a trans-conformation, while an amorphous region is mostly in a cis-conformation, and the molecular arrangement of the amorphous region is quite tight, so that the dyeing difficulty of the polyester fiber is further increased. At present, Polyester (PET) fibers are generally dyed by using disperse dyes at high temperature (130 ℃) and high pressure, the dye-uptake of the fibers can be ensured only by dyeing at high temperature and high pressure, the requirements of the high temperature and high pressure on equipment are high, the energy consumption is high, meanwhile, the dyeing difficulty is high, the required time for dyeing is long, the cost of the process is high, and the application of the high-strength polyester fibers is limited to a certain extent.

Therefore, the polyester industrial yarn for the safety belt for the aerial work, which has good dyeing property, needs to be researched.

Disclosure of Invention

The invention aims to overcome the problems in the prior art and provide the polyester industrial yarn for the safety belt for high-altitude operation and the preparation method thereof, wherein the polyester industrial yarn has good dyeing property.

In order to achieve the purpose, the invention adopts the technical scheme that:

the preparation method of the polyester industrial yarn for the aerial work safety belt comprises the following steps of carrying out solid-phase polycondensation tackifying, melting, metering, extruding, cooling, oiling, stretching, heat setting and winding on a modified polyester melt to prepare the polyester industrial yarn for the aerial work safety belt;

the preparation method of the modified polyester before solid-phase polycondensation tackifying comprises the following steps: uniformly mixing terephthalic acid, ethylene glycol, dihydric alcohol with trimethylsilyl lateral group, hexanediol with tert-butyl lateral group and zinc oxide powder, and then carrying out esterification reaction and polycondensation reaction in sequence; the content of zinc oxide powder in the modified polyester before solid-phase polycondensation and tackifying is 0.3-0.5 wt%, and the average particle size of the zinc oxide powder is less than 0.3 micron;

the structural formulas of the dihydric alcohol with the trimethylsilyl lateral group and the hexanediol with the tert-butyl lateral group are respectively shown as a formula (I) and a formula (II):

in the formula (I), R is-CH₂-、-CH(CH₃) -or-C ((CH)₃)₂) -, in the formula (II), R is-H or-CH₂CH₃or-C (CH)₃)₃。

The invention adopts the dihydric alcohol with the trimethylsilyl lateral group and the hexanediol with the tertiary butyl lateral group as reactants in the polyester synthesis process, thereby improving the dyeing effect of the polyester industrial yarn, and the method specifically comprises the following steps:

the existence of the tertiary butyl group in hexanediol with the tertiary butyl group side group can cause the change of the activity of a main chain, thereby changing the interaction force among chain units, and correspondingly changing the distance among the chain units, so that the free volume of a cavity of the modified polyester is increased. The diol with the trimethylsilyl lateral group can also obviously increase the space free volume of the modified polyester, particularly the existence of the trimethylsilyl group in the diol with the trimethylsilyl lateral group can cause the change of the activity of a main chain, so that the interaction force among chain units is changed, the distance among molecular chain units can be correspondingly changed, the cavity free volume of the modified polyester is increased, the difficulty of dye molecules penetrating into the modified polyester can be reduced by increasing the cavity free volume, the dyeing performance of the modified polyester is improved, the dyeing temperature is reduced, the dyeing time is shortened, the energy consumption is reduced, and the dyeing rate of the modified polyester is improved. The disperse dyes are dyes with small molecular weight and no water-soluble group on the structure, most of which exist in the form of particles with the particle diameter of hundreds of nanometers to one micron. The dye has a very low dye-uptake rate within 100 ℃, even if the dye is dyed in a boiling dye bath, the dye-uptake rate and the dye-uptake percentage are not high, along with the continuous improvement of the temperature, the side group in the polyester macromolecular chain starts to move before the molecular chain, when the temperature of the dye bath is improved to 120-130 ℃, the intensity of the movement of the side group is greater than that of the molecular chain, and when the granular dye diffuses into the fiber, the free volume of a cavity formed by the dihydric alcohol with the trimethylsilyl side group and the hexanediol with the tert-butyl side group is larger than that of a slit formed by the molecular chain, and the diffusion rate is higher.

As a preferred technical scheme:

according to the preparation method of the polyester industrial yarn for the aerial work safety belt, the synthesis steps of the dihydric alcohol with the trimethylsilyl lateral group are as follows:

(1) mixing raw materials of alkene, peracetic acid and dichloromethane according to a molar ratio of 1: 5-10: 10-15, reacting for 5-8 hours at the temperature of 35-40 ℃, stirring during the reaction, removing a solvent after the reaction is finished, and purifying and refining to obtain the trimethylsilyl propylene epoxide;

(2) mixing water, concentrated sulfuric acid and trimethylsilyl propylene epoxide, heating the mixture to 80-85 ℃ in a water bath under the stirring condition, carrying out heat preservation reaction for l 0-15 min, cooling the mixture to room temperature after the reaction is finished, and carrying out neutralization, distillation, separation and purification to obtain dihydric alcohol with a trimethylsilyl lateral group, wherein the concentrated sulfuric acid is sulfuric acid with the mass concentration of 70%, the molar ratio of the trimethylsilyl propylene epoxide to the water is 1: 20-40 at the beginning of the reaction, and the mass of the concentrated sulfuric acid accounts for 0.1-0.15% of the total mass of the mixture;

in the formula (I), R is-CH (CH)₃) -and-C ((CH)₃)₂) -when said starting alkenes correspond to 3-trimethylsilyl-3-methylpropene and 3-trimethylsilyl-3, 3-dimethylpropene;

the synthesis method of the hexanediol with the tert-butyl side group comprises the following steps: firstly, mixing a raw material solution A with the concentration of 300-350 g/L and a dilute sulfuric acid solution with the concentration of 200-300 g/L according to the molar ratio of the raw material A to sulfuric acid of 1.5-2: 1, adding the mixture into a cathode electrolytic cell, then cooling the mixed solution to 10-15 ℃, carrying out electrolytic reduction until the concentration of the raw material A is lower than 10 wt%, and finally carrying out cooling crystallization, separation and purification;

in the formula (II), R is-H, -CH₂CH₃and-C(CH₃)₃In this case, the raw material A is 2, 2-methylpropionaldehyde, 2-dimethyl-3-pentanone, and 2,24, 4-tetramethyl-3-pentanone, respectively.

According to the preparation method of the polyester industrial yarn for the aerial work safety belt, the preparation steps of the modified polyester before solid-phase polycondensation and tackifying are as follows:

(1) performing esterification reaction;

preparing terephthalic acid, ethylene glycol, dihydric alcohol with trimethylsilyl lateral group and hexanediol with tert-butyl lateral group into slurry, adding zinc oxide powder, a catalyst, a delustering agent and a stabilizer, uniformly mixing, pressurizing in a nitrogen atmosphere to perform esterification reaction, wherein the pressurizing pressure is normal pressure to 0.3MPa, the esterification reaction temperature is 250-260 ℃, and the esterification reaction end point is determined when the water distillate in the esterification reaction reaches more than 90% of the theoretical value;

(2) performing polycondensation reaction;

after the esterification reaction is finished, starting the polycondensation reaction in a low vacuum stage under the condition of negative pressure, wherein the pressure in the stage is stably pumped from normal pressure to below 500Pa in 30-50 min, the reaction temperature is 250-260 ℃, the reaction time is 30-50 min, then continuously pumping vacuum to perform the polycondensation reaction in a high vacuum stage, so that the reaction pressure is further reduced to below 100Pa, the reaction temperature is 270-282 ℃, and the reaction time is 50-90 min.

According to the preparation method of the polyester industrial yarn for the aerial work safety belt, the molar ratio of the terephthalic acid, the ethylene glycol, the dihydric alcohol with the trimethylsilyl lateral group and the hexanediol with the tert-butyl lateral group is 1: 1.2-2.0: 0.02-0.03: 0.01-0.02; the content of hexanediol with tertiary butyl side groups can be adjusted within a proper range, but the content is not too high or too low, the mechanical property of the fiber is influenced to a certain extent by too high, and the too low effect is not obvious; the addition amount of the diol with the trimethylsilyl group side group is not limited to the above, and a person skilled in the art can adjust the actual condition, but the adjustment range is not too large, the excessive addition amount has too large damage to the regularity of the polyester macromolecular structure, the influence on the crystallinity and the mechanical property of the fiber is too large, the production and the application of the fiber are not facilitated, and the effect is not obvious if the addition amount is too low; the adding amount of the zinc oxide powder, the catalyst, the flatting agent and the stabilizer is respectively 0.3-0.5 wt%, 0.03-0.05 wt%, 0.20-0.25 wt% and 0.01-0.05 wt% (mass percentage) of the adding amount of the terephthalic acid.

According to the preparation method of the polyester industrial yarn for the aerial work safety belt, the catalyst is antimony trioxide, ethylene glycol antimony or antimony acetate, the delustering agent is titanium dioxide, and the stabilizer is triphenyl phosphate, trimethyl phosphate or trimethyl phosphite.

According to the preparation method of the polyester industrial yarn for the aerial work safety belt, the intrinsic viscosity of the modified polyester after solid-phase polycondensation tackifying is 1.0-1.2 dL/g, the intrinsic viscosity can be adjusted within a proper range, but the intrinsic viscosity is not too high or too low, the spinnability is reduced if the intrinsic viscosity is too high, and the molecular weight of the polyester is too low if the intrinsic viscosity is too low, so that the requirements of the industrial yarn cannot be met.

According to the preparation method of the polyester industrial yarn for the aerial work safety belt, the spinning process parameters of the polyester industrial yarn for the aerial work safety belt are as follows:

the technological parameters of stretching and heat setting are as follows:

the invention also provides the polyester industrial yarn for the aerial work safety belt, which is prepared by the preparation method of the polyester industrial yarn for the aerial work safety belt, and the material of the polyester industrial yarn is modified polyester;

the molecular chain of the modified polyester comprises a terephthalic acid chain segment, an ethylene glycol chain segment, a diol chain segment with a trimethylsilyl lateral group and a hexanediol chain segment with a tert-butyl lateral group; the modified polyester contains zinc oxide powder.

As a preferred technical scheme:

the terylene industrial yarn for the safety belt for overhead operation has the filament number of 8.5-12.5 dtex, the multifilament number of 1100-1700 dtex, the breaking strength of more than or equal to 8.1cN/dtex, the deviation rate of linear density of +/-1.5%, the CV value of the breaking strength of less than or equal to 3.0%, the elongation at break of 13.0-16.5%, the CV value of the elongation at break of less than or equal to 8.0%, the central value of the elongation of 4.0cN/dtex load of 4.8-6.3%, the deviation rate of the elongation of 4.0cN/dtex load of +/-0.8%, the dry heat shrinkage rate of 7.0-9.5% under the condition of 177 ℃ x 10min x 0.05cN/dtex, the network degree of (5-8) ± 2/m, and the oil content of 0.6 +/-0.2 wt%, and the mechanical properties of the fiber prepared by modification are equivalent to those of the prior art.

According to the polyester industrial yarn for the safety belt for the aerial work, the light fastness of the polyester industrial yarn for the safety belt for the aerial work is 7-8 grade, the ultraviolet transmittance is less than 5 percent, the dye uptake (selected from Resolin disperse dyes, C.I. disperse yellow 93, C.I. disperse orange 66 and the like) at the temperature of 130 ℃ is 88.4-93.7 percent, and the K/S value is 24.24-26.56; under the same other test conditions, the dye uptake of the comparative sample under the temperature condition of 130 ℃ is 84.8%, the K/S value is 22.07, and the comparative sample is different from the polyester industrial yarn only in that the material is a diol chain segment without introducing a trimethylsilyl group into a polyester molecular chain and a hexanediol chain segment with a tert-butyl group.

The invention mechanism is as follows:

the macromolecular chains in the polymer are not completely tightly packed, and voids always exist among the macromolecular chains, and the void volume is the free volume. Since small molecules are allowed to penetrate into the polymer, voids are sufficiently large in the polymer or between the polymers, the permeability and diffusivity of the small molecules are related to the size of the voids (i.e., the size of free volume) in the polymer structure, and within a certain range, the larger the size of the free volume, the higher the permeability of the small molecules, and the better the diffusivity. The free volume is divided into a cavity free volume and a slit free volume, the cavity free volume has larger space size than the slit free volume, and the effect of the cavity free volume is more obvious than the effect of the slit free volume for improving the permeability of small molecules.

The size and type of free volume depends primarily on the structure of the polymer, and the primary factors affecting the polymer structure are steric hindrance, pendant group size, pendant group structure, and the like. When a certain position on the main chain of the polymer is substituted by a side group, the activity of the main chain is inevitably changed, so that the interaction force between chains is changed, the distance between the chains is also correspondingly changed, and consequently, the cohesive energy and the free volume are changed, and the polarity, the size, the length and the like of the substituent on the side chain of the polymer have certain influences on the rigidity of the molecular chain, the interaction between molecules and the free volume fraction of the polymer structure, so that the effects generated by different substituents are different, and the osmotic separation performance of the polymer is often different.

For glycol straight chain molecules such as ethylene glycol and butanediol, the C atoms on the main chain are arranged in a zigzag manner from top to bottom, and when the H atom on a certain methylene on the main chain is replaced by a methyl group (-CH)₃) When in substitution, the C atoms on the side groups and the main chain C atoms are not in the same plane, so that four sp3 hybridized orbitals on the center C are respectively overlapped with empty orbitals on the four surrounding C atoms to form four completely same sigma bonds which are arranged in a regular tetrahedron, the four carbon atoms are respectively positioned at four vertexes of the regular tetrahedron, when three hydrogen of a methyl group is further substituted by the methyl group, the three hydrogen is equivalent to tert-butyl to form a larger tetrahedron structure, and compared with the molecular chain which is arranged in a zigzag manner, the molecular chain which is arranged in the regular tetrahedron manner has the advantages that the free volume of the empty hole is obviously increased, and the permeability and the diffusivity of small molecules can be obviously improved; when the H atom on a certain methylene on the main chain is replaced by a long branched chain substituent, the main increase is the slit free volume, and the increase rangeSmaller, the improvement effect on the permeability and diffusivity of small molecules is limited, and meanwhile, the long branched chain substituent has smaller rigidity, so that molecular chains are easy to tangle, and the increase of free volume is not facilitated.

The structural formula of the hexanediol with the tertiary butyl side group is as follows:

wherein R is-H (hexanediol with tert-butyl side group is 2,2,5, 5-tetramethyl-3, 4-hexanediol), -CH₂CH₃(hexanediol with pendant tert-butyl groups is 2,2,5, 5-tetramethyl-3, 4-diethyl-3, 4-hexanediol) or-C (CH)₃)₃(hexanediol with pendant tert-butyl groups is 2,2,4, 4-tetramethyl-3, 4-di-tert-butyl-3, 4-hexanediol);

the existence of the tertiary butyl group in hexanediol with the tertiary butyl group side group can cause the change of the activity of a main chain, thereby changing the interaction force among chain units, and correspondingly changing the distance among the chain units, so that the free volume of a cavity of the modified polyester is increased. Compared with short-chain substituent groups (such as methyl, ethyl and the like), the tertiary butyl group occupies a larger spatial position, and a larger free volume is obtained in the molecular chain arrangement mode; compared with the long-branched-chain substituent, on one hand, the tertiary butyl group has a hollow space and the long-branched-chain substituent has a slit free volume, and on the other hand, the rigidity of the tertiary butyl group is higher than that of the long-branched-chain substituent, so that entanglement among molecular chains is reduced, and the tertiary butyl group has more free volume than the long-branched-chain substituent in the arrangement mode of the molecular chains. Because the polyester has high crystallinity and smooth surface, few surface active groups and unsatisfactory activation effect, and the introduction of the hexanediol with the tert-butyl side group increases the free volume of the cavity of the modified polyester.

The structural formula of the diol with the trimethylsilyl lateral group is as follows:

in the formulaR is-CH₂- (diols with trimethylsilyl side group being 3-trimethylsilyl-1, 2-propanediol), -CH (CH)₃) - (diols with trimethylsilyl side groups being 3-trimethylsilyl-3-methyl-1, 2-propanediol) or-C ((CH)₃)₂) - (the diol having trimethylsilyl side groups is 3-trimethylsilyl-3, 3-dimethyl-1, 2-propanediol).

For ethylene glycol straight chain molecules, the C atoms on the main chain are arranged in a zigzag arrangement from top to bottom, and when the H atom on a certain methylene on the main chain is replaced by a methyl group (-CH)₃) When in substitution, the C atom on the substituent group and the main chain C atom are not in the same plane, so that four sp3 hybridized orbitals on the center C are respectively overlapped with empty orbitals on the four surrounding C atoms to form four completely same sigma bonds which are arranged in a regular tetrahedron, the four carbon atoms are respectively positioned at four vertexes of the regular tetrahedron, when three hydrogen of the methyl group is further substituted by methyl or trimethylsilyl, a larger tetrahedron structure can be formed, compared with the molecular chain which is arranged in a zigzag manner, the molecular chain which is arranged in the regular tetrahedron shape has the advantages that the free volume of the empty hole is greatly increased, the permeability and the diffusivity of small molecules can be obviously improved, in addition, the bond length of the carbon-silicon bond in the trimethylsilyl group is larger than that of the carbon-carbon bond, the atom free rotation is facilitated, and the free volume of the empty hole is; when the H atom on a certain methylene on the main chain is replaced by the long branched chain substituent, the slit free volume is mainly increased, the increase amplitude is small, the improvement effect on the permeability and the diffusivity of the micromolecule is limited, and meanwhile, the long branched chain substituent has low rigidity, the molecular chains are easy to tangle, and the increase of the free volume is not facilitated.

The existence of trimethylsilyl in the diol with trimethylsilyl lateral groups can cause the change of the activity of a main chain, thereby changing the interaction force among chain units, and correspondingly changing the distance among molecular chain units, so that the free volume of the cavity of the modified polyester is increased. Compared with short-branched-chain substituent groups (such as methyl groups, ethyl groups and the like), the trimethylsilyl group occupies a larger spatial position, and a larger free volume is obtained in the molecular chain arrangement mode; compared with the long-branched-chain substituent, on one hand, the increased free volume of the trimethylsilyl group is more hollow free volume, while the increased free volume of the long-branched-chain substituent is more slit free volume, and on the other hand, the rigidity of the trimethylsilyl group is higher than that of the long-branched-chain substituent, so that the entanglement among molecular chains is reduced, and therefore, the longer-branched-chain substituent of the trimethylsilyl group has more free volume in the molecular chain arrangement mode. The introduction of the diol with trimethylsilyl lateral groups increases the spatial free volume of the modified polyester, and particularly the increase of the free volume of a cavity is more obvious.

The increase of the free volume of the space enables water or other molecules such as dye to permeate into the modified polyester macromolecules more easily, positive influence is generated on the dyeing of the modified polyester, the problem that the dyeing difficulty of common polyester is too large due to too tight molecular arrangement is solved, the dyeing temperature is reduced, the dyeing time is shortened, the energy consumption is reduced, and meanwhile, the dyeing rate of fibers is also improved.

Has the advantages that:

(1) according to the polyester industrial yarn for the aerial work safety belt and the preparation method thereof, the dyeing property of the polyester industrial yarn is remarkably improved by introducing the modified components, namely the dihydric alcohol with the trimethylsilyl lateral group and the hexanediol with the tert-butyl lateral group into the polyester;

(2) the polyester industrial yarn for the aerial work safety belt has the advantages of excellent dyeing performance, excellent mechanical performance and good application prospect.

Drawings

FIG. 1 is a schematic diagram of a reaction apparatus for synthesizing hexanediol with a tertiary butyl side group according to the present invention.

Detailed Description

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

Example 1

A preparation method of polyester industrial yarn for aerial work safety belts comprises the following specific steps:

(1) preparing modified polyester;

(1.1) synthesizing 2,2,5, 5-tetramethyl-3, 4-hexanediol by the following steps: firstly, mixing a 2, 2-methylpropionaldehyde solution with the concentration of 320g/L and a dilute sulfuric acid solution with the concentration of 200g/L according to the molar ratio of 2, 2-methylpropionaldehyde to sulfuric acid of 1.5:1, adding the mixture into a cathode electrolytic cell, then cooling the mixed solution to 12 ℃, then carrying out electrolytic reduction to the concentration of 2, 2-methylpropionaldehyde of 9.5 wt%, and finally carrying out cooling crystallization, separation and purification, wherein the schematic diagram of a reaction device adopted in the synthetic process is shown in figure 1, and the reaction chemical equation is as follows:

the structural formula of the prepared 2,2,5, 5-tetramethyl-3, 4-hexanediol is shown as a formula (I), wherein R is-H;

(1.2) esterification reaction;

preparing terephthalic acid, ethylene glycol, 3-trimethylsilyl-1, 2-propanediol and 2,2,5, 5-tetramethyl-3, 4-hexanediol with the molar ratio of 1:1.2:0.02:0.01 into slurry, adding zinc oxide powder, antimony trioxide, titanium dioxide and triphenyl phosphate, uniformly mixing, pressurizing in a nitrogen atmosphere to perform esterification reaction, wherein the pressurizing pressure is 0.1MPa, the esterification reaction temperature is 250 ℃, the esterification reaction end point is the end point when the distilled water amount in the esterification reaction reaches 93% of a theoretical value, the adding amounts of the zinc oxide powder, the antimony trioxide, the titanium dioxide and the triphenyl phosphate are respectively 0.3 wt%, 0.03 wt%, 0.20 wt% and 0.02 wt% of the adding amount of the terephthalic acid, and the average particle size of the zinc oxide powder is 0.29 micron;

(1.3) a polycondensation reaction;

after the esterification reaction is finished, starting the polycondensation reaction in the low vacuum stage under the negative pressure condition, stably pumping the pressure in the stage from normal pressure to absolute pressure of 480Pa within 30min, controlling the reaction temperature to be 250 ℃ and the reaction time to be 31min, then continuing pumping vacuum, and carrying out the polycondensation reaction in the high vacuum stage to further reduce the reaction pressure to absolute pressure of 100Pa, control the reaction temperature to be 270 ℃ and control the reaction time to be 50min, thus obtaining the modified polyester;

(1.4) carrying out solid phase polycondensation tackifying on the modified polyester to obtain a modified polyester melt with the intrinsic viscosity of 1.0 dL/g;

(2) the modified polyester melt is subjected to melting, metering, extruding, cooling, oiling, stretching, heat setting and winding to prepare the polyester industrial yarn for the aerial work safety belt, and the spinning process parameters are as follows:

the technological parameters of stretching and heat setting are as follows:

the finally prepared polyester industrial yarn for the aerial work safety belt has the filament number of 12.5dtex, the multifilament number of 1700dtex, the breaking strength of 8.4cN/dtex, the deviation rate of linear density of 0.5%, the CV value of the breaking strength of 2.4%, the elongation at break of 16.5%, the CV value of the elongation at break of 6.4%, the central value of the elongation at 4.0cN/dtex load of 6.3%, the deviation rate of the elongation at 4.0cN/dtex load of 0.3%, the dry heat shrinkage rate under the conditions of 177 ℃ multiplied by 10min multiplied by 0.05cN/dtex of 9.5%, the network degree of 10/m, the oil content of 0.8 wt%, the light fastness of 7 grade and the ultraviolet transmittance of 4.9%; the dye uptake under the temperature condition of 130 ℃ is 88.4 percent, and the K/S value is 24.24.

Comparative example 1

The preparation method of the polyester industrial yarn comprises the following specific steps which are basically the same as those in the example 1, and is different from the specific steps in that 3-trimethylsilyl-1, 2-propanediol and 2,2,5, 5-tetramethyl-3, 4-hexanediol are not added in the step (1). The finally prepared polyester industrial yarn has the filament number of 12.5dtex, the multifilament number of 1700dtex, the breaking strength of 8.3cN/dtex, the deviation rate of linear density of 0.4%, the breaking strength CV value of 2.4%, the elongation at break of 16.0%, the elongation at break CV value of 6.4%, the central value of the elongation at 4.0cN/dtex load of 6.3%, the deviation rate of the elongation at 4.0cN/dtex load of 0.3%, the dry heat shrinkage rate of 9.3% under the conditions of 177 ℃ multiplied by 10min multiplied by 0.05cN/dtex, the network degree of 10/m, the oil content of 0.8 wt%, the light fastness of 7 grade and the ultraviolet transmittance of 4.7 grade; under the same conditions as other test conditions of example 1, the dye uptake under the temperature condition of 130 ℃ was 84.3%, and the K/S value was 21.76.

Comparative example 2

The preparation method of the polyester industrial yarn is basically the same as that of the example 1, and is different from the step (1) in that 3-trimethylsilyl-1, 2-propanediol is not added. The finally prepared polyester industrial yarn has the filament number of 12.5dtex, the multifilament number of 1700dtex, the breaking strength of 8.5cN/dtex, the deviation rate of linear density of 0.8%, the CV value of breaking strength of 2.4%, the elongation at break of 15.5%, the CV value of elongation at break of 6.4%, the central value of the elongation at 4.0cN/dtex load of 6.3%, the deviation rate of the elongation at 4.0cN/dtex load of 0.3%, the dry heat shrinkage rate of 9.2% under the conditions of 177 ℃ multiplied by 10min multiplied by 0.05cN/dtex, the network degree of 10/m, the oil content of 0.8 wt%, the light fastness of 7 grade and the ultraviolet transmittance of 4.2%; under the same conditions as other test conditions of example 1, the dye uptake under the temperature condition of 130 ℃ was 86.7%, and the K/S value was 23.56.

Comparative example 3

The preparation method of the polyester industrial yarn is basically the same as that of the example 1, and is different from the step (1) in that 2,2,5, 5-tetramethyl-3, 4-hexanediol is not added. The finally prepared polyester industrial yarn has the filament number of 12.5dtex, the multifilament number of 1700dtex, the breaking strength of 8.4cN/dtex, the deviation rate of linear density of 0.5%, the breaking strength CV value of 2.4%, the elongation at break of 14.7%, the elongation at break CV value of 6.4%, the central value of the elongation at 4.0cN/dtex load of 6.3%, the deviation rate of the elongation at 4.0cN/dtex load of 0.3%, the dry heat shrinkage rate of 9.5% under the conditions of 177 ℃ multiplied by 10min multiplied by 0.05cN/dtex, the network degree of 10/m, the oil content of 0.8 wt%, the light fastness of 7 level and the ultraviolet transmittance of 4.5%; under the same conditions as other test conditions of example 1, the dye uptake under the temperature condition of 130 ℃ was 87.4%, and the K/S value was 22.47.

Comprehensive analysis of example 1 and comparative examples 1 to 3 shows that the dyeing property and the ultraviolet resistance of the fiber are significantly improved by adding 3-trimethylsilyl-1, 2-propanediol and 2,2,5, 5-tetramethyl-3, 4-hexanediol, wherein the 3-trimethylsilyl-1, 2-propanediol and 2,2,5, 5-tetramethyl-3, 4-hexanediol are cooperated with each other to jointly increase the cavity free volume of the polyester, reduce the difficulty of dye molecules and ultraviolet resistance molecules entering the fiber, and improve the dyeing property and the ultraviolet resistance. In addition, the addition of 3-trimethylsilyl-1, 2-propanediol and 2,2,5, 5-tetramethyl-3, 4-hexanediol has little influence on other properties of the fiber, and does not influence the processability and mechanical properties of the fiber.

Comparative example 4

The preparation method of the polyester industrial yarn is basically the same as that in the example 1, and is different from the step 1 in that 1, 2-dodecyl glycol is adopted to replace 2,2,5, 5-tetramethyl-3, 4-hexanediol. The finally prepared polyester industrial yarn has the filament number of 12.5dtex, the multifilament number of 1700dtex, the breaking strength of 8.5cN/dtex, the deviation rate of linear density of 0.5%, the breaking strength CV value of 2.4%, the elongation at break of 16.8%, the elongation at break CV value of 6.4%, the central value of the elongation at 4.0cN/dtex load of 6.3%, the deviation rate of the elongation at 4.0cN/dtex load of 0.3%, the dry heat shrinkage rate of 9.5% under the conditions of 177 ℃ multiplied by 10min multiplied by 0.05cN/dtex, the network degree of 10/m, the oil content of 0.8 wt%, the light fastness of 7 grade and the ultraviolet transmittance of 4.3%; under the same conditions as other test conditions of example 1, the dye uptake under the temperature condition of 130 ℃ was 86.6%, and the K/S value was 23.11.

Compared with example 1, it can be found that the hexanediol with the tertiary butyl side group is more favorable for improving the dyeing performance of the fiber compared with the long branched chain substituent, mainly because the hexanediol with the tertiary butyl side group on one side has more increased free volume which is cavity free volume, the hexanediol with the long branched chain substituent has more increased free volume which is slit free volume, and the hexanediol with the tertiary butyl side group on the other side has higher rigidity than the long branched chain substituent, so that the entanglement between molecular chains is reduced, and the hexanediol with the tertiary butyl side group has more free volume in the molecular chain arrangement mode compared with the long branched chain substituent, thereby being more favorable for improving the dyeing performance and the ultraviolet resistance of the fiber.

Comparative example 5

The preparation method of the polyester industrial yarn is basically the same as that in the example 1, and is different from the step 1 in that 1, 2-dodecyl glycol is adopted to replace 3-trimethylsilyl-1, 2-propylene glycol. The finally prepared polyester industrial yarn has the filament number of 12.5dtex, the multifilament number of 1700dtex, the breaking strength of 8.3cN/dtex, the deviation rate of linear density of 0.5%, the breaking strength CV value of 2.4%, the elongation at break of 16.0%, the elongation at break CV value of 6.4%, the central value of the elongation at 4.0cN/dtex load of 6.3%, the deviation rate of the elongation at 4.0cN/dtex load of 0.3%, the dry heat shrinkage rate of 9.5% under the conditions of 177 ℃ multiplied by 10min multiplied by 0.05cN/dtex, the network degree of 10/m, the oil content of 0.8 wt%, the light fastness of 7 grade and the ultraviolet transmittance of 4.8%; under the same conditions as other test conditions of example 1, the dye uptake under the temperature condition of 130 ℃ was 86.1%, and the K/S value was 22.87.

Compared with the example 1, it can be found that the trimethylsilyl group is more favorable for improving the dyeing performance of the fiber compared with the long-branched chain substituent, mainly because the increased free volume of the trimethylsilyl group is more hollow free volume, while the increased free volume of the long-branched chain substituent is more slit free volume, and on the other hand, the rigidity of the trimethylsilyl group is greater than that of the long-branched chain substituent, so that the entanglement among molecular chains is reduced, and therefore, the longer-branched chain substituent of the trimethylsilyl group has more free volume in the molecular chain arrangement mode, and further, the dyeing performance and the ultraviolet resistance of the fiber are more favorable for improving.

Example 2

(1) preparing modified polyester;

(1.1) Synthesis of 2,2,5, 5-tetramethyl-3, 4-diethyl-3, 4-hexanediol, ProcessThe method comprises the following steps: firstly, mixing a 2, 2-dimethyl 3-pentanone solution with the concentration of 350g/L and a dilute sulfuric acid solution with the concentration of 210g/L according to the molar ratio of the 2, 2-dimethyl 3-pentanone to the sulfuric acid of 1.6:1, adding the mixture into a cathode electrolytic cell, then cooling the mixed solution to 11 ℃, carrying out electrolytic reduction to the concentration of 9.0 wt% of the 2, 2-dimethyl 3-pentanone, and finally carrying out cooling crystallization, separation and purification, wherein a reaction device and a reaction chemical equation adopted in the synthetic process are consistent with those of example 1, and the structural formula of the prepared 2,2,5, 5-tetramethyl-3, 4-diethyl-3, 4-hexanediol is shown as a formula (I), wherein R is-CH (CH)₂CH₃；

(1.2) preparing 3-trimethylsilyl-3-methyl-1, 2-propanediol;

(1.2.1) mixing 3-trimethylsilyl-3-methylpropene, peracetic acid and dichloromethane according to the molar ratio of 1:5:10, reacting for 5 hours at the temperature of 35 ℃, stirring during the reaction, removing the solvent after the reaction is finished, and purifying and refining to obtain trimethylsilyl propylene epoxide;

(1.2.2) mixing water, concentrated sulfuric acid and trimethylsilyl propylene epoxide, heating the mixture in water bath to 80 ℃ under the condition of stirring, preserving the heat for reaction for 10min, cooling the mixture to room temperature after the reaction is finished, and neutralizing, distilling, separating and purifying the mixture to obtain the 3-trimethylsilyl-3-methyl-1, 2-propylene glycol shown as the formula (II), wherein R in the formula (II) is-CH (CH)₃) The concentrated sulfuric acid is sulfuric acid with the mass concentration of 70%, the molar ratio of the trimethylsilyl propylene epoxide to water is 1:20 when the reaction starts, and the mass of the concentrated sulfuric acid accounts for 0.1% of the mass sum of the mixture;

(1.3) esterification reaction;

preparing terephthalic acid, ethylene glycol, 3-trimethylsilyl-3-methyl-1, 2-propanediol and 2,2,5, 5-tetramethyl-3, 4-diethyl-3, 4-hexanediol with the molar ratio of 1:1.5:0.025:0.015 into slurry, adding zinc oxide powder, ethylene glycol antimony, titanium dioxide and trimethyl phosphate, uniformly mixing, pressurizing in a nitrogen atmosphere to perform esterification reaction, wherein the pressurizing pressure is normal pressure, the esterification reaction temperature is 251 ℃, the esterification reaction endpoint is when the water distillation amount in the esterification reaction reaches 92% of a theoretical value, the adding amounts of the zinc oxide powder, the ethylene glycol antimony, the titanium dioxide and the trimethyl phosphate are respectively 0.4 wt%, 0.04 wt%, 0.22 wt% and 0.01 wt% of the adding amount of the terephthalic acid, and the average particle size of the zinc oxide powder is 0.24 micron;

(1.4) a polycondensation reaction;

after the esterification reaction is finished, starting the polycondensation reaction in a low vacuum stage under the condition of negative pressure, stably pumping the pressure in the stage from normal pressure to the absolute pressure of 500Pa within 30min, controlling the reaction temperature to be 252 ℃ and the reaction time to be 30min, then continuing to pump vacuum, and carrying out the polycondensation reaction in a high vacuum stage to further reduce the reaction pressure to the absolute pressure of 100Pa, control the reaction temperature to be 271 ℃ and control the reaction time to be 55min, thus obtaining the modified polyester;

(1.5) carrying out solid phase polycondensation tackifying on the modified polyester to obtain a modified polyester melt with the intrinsic viscosity of 1.0 dL/g;

the technological parameters of stretching and heat setting are as follows:

the finally prepared polyester industrial yarn for the aerial work safety belt has the filament number of 10.5dtex, the multifilament number of 1400dtex, the breaking strength of 8.5cN/dtex, the deviation rate of linear density of 1.0%, the CV value of the breaking strength of 2.7%, the elongation at break of 15.0%, the CV value of the elongation at break of 7.2%, the central value of the elongation at 4.0cN/dtex load of 5.5%, the deviation rate of the elongation at 4.0cN/dtex load of-0.4%, the dry heat shrinkage rate under the conditions of 177 ℃ multiplied by 10min multiplied by 0.05cN/dtex of 8.2%, the network degree of 7/m, the oil content of 0.6 wt%, the light fastness of 7 level and the ultraviolet transmittance of 4.5%; the dye uptake under the temperature condition of 130 ℃ is 91.4 percent, and the K/S value is 25.34.

Example 3

(1) preparing modified polyester;

(1.1) synthesizing 2,2,4, 4-tetramethyl-3, 4-di-tert-butyl-3, 4-hexanediol by the following steps: firstly, mixing a 2,24, 4-tetramethyl-3-pentanone solution with the concentration of 340g/L and a dilute sulfuric acid solution with the concentration of 230g/L according to the molar ratio of the 2,24, 4-tetramethyl-3-pentanone to the sulfuric acid of 1.7:1, adding the mixture into a cathode electrolytic cell, then cooling the mixed solution to 10 ℃, carrying out electrolytic reduction until the concentration of the 2,24, 4-tetramethyl-3-pentanone is 9.6 wt%, and finally carrying out cooling crystallization, separation and purification, wherein a reaction device and a reaction chemical equation adopted in the synthetic process are consistent with those of example 1, and the structural formula of the prepared 2,2,4, 4-tetramethyl-3, 4-di-tert-butyl-3, 4-hexanediol is shown as a formula (I), wherein R is-C (CH) (CH 3, 4-hexanediol)₃)₃；

(1.2) preparing 3-trimethylsilyl-3-methyl-1, 2-propanediol;

(1.2.1) mixing 3-trimethylsilyl-3-methylpropene, peracetic acid and dichloromethane according to the molar ratio of 1:10:15, reacting for 8 hours at the temperature of 40 ℃, stirring during the reaction, removing the solvent after the reaction is finished, and purifying and refining to obtain trimethylsilyl propylene epoxide;

(1.2.2) mixing water, concentrated sulfuric acid and trimethylsilyl propylene epoxide, heating the mixture in water bath to 85 ℃ under the condition of stirring, preserving the heat for reaction for 15min, cooling the mixture to room temperature after the reaction is finished, and neutralizing, distilling, separating and purifying the mixture to obtain the 3-trimethylsilyl-3-methyl-1, 2-propylene glycol shown as the formula (II), wherein R in the formula (II) is-CH (CH)₃) The concentrated sulfuric acid is sulfuric acid with the mass concentration of 70%, the molar ratio of the trimethylsilyl propylene epoxide to water is 1:40 when the reaction starts, and the mass of the concentrated sulfuric acid accounts for 0.15% of the mass sum of the mixture;

(1.3) esterification reaction;

preparing terephthalic acid, ethylene glycol, 3-trimethylsilyl-3-methyl-1, 2-propanediol and 2,2,4, 4-tetramethyl-3, 4-di-tert-butyl-3, 4-hexanediol with the molar ratio of 1:1.8:0.022:0.013 into slurry, adding zinc oxide powder, antimony acetate, titanium dioxide and trimethyl phosphite, uniformly mixing, pressurizing in a nitrogen atmosphere to perform esterification reaction, wherein the pressurizing pressure is normal pressure, the esterification reaction temperature is 252 ℃, the esterification reaction endpoint is when the water distillation amount in the esterification reaction reaches 90% of a theoretical value, the adding amounts of the zinc oxide powder, the antimony acetate, the titanium dioxide and the trimethyl phosphite are respectively 0.4 wt%, 0.04 wt%, 0.23 wt% and 0.03 wt% of the adding amount of the terephthalic acid, and the average particle size of the zinc oxide powder is 0.27 micrometers;

(1.4) a polycondensation reaction;

after the esterification reaction is finished, starting the polycondensation reaction in the low vacuum stage under the negative pressure condition, smoothly pumping the pressure in the low vacuum stage from normal pressure to the absolute pressure of 450Pa within 35min, controlling the reaction temperature to 253 ℃ and controlling the reaction time to 35min, then continuously pumping the vacuum to perform the polycondensation reaction in the high vacuum stage, further reducing the reaction pressure to the absolute pressure of 90Pa, controlling the reaction temperature to 274 ℃ and controlling the reaction time to 60min, and preparing the modified polyester;

(1.5) carrying out solid phase polycondensation tackifying on the modified polyester to obtain a modified polyester melt with the intrinsic viscosity of 1.1 dL/g;

the technological parameters of stretching and heat setting are as follows:

the finally prepared polyester industrial yarn for the aerial work safety belt has the filament number of 11.0dtex, the multifilament number of 1500dtex, the breaking strength of 8.6cN/dtex, the deviation rate of linear density of +/-0.9%, the CV value of the breaking strength of 2.6%, the elongation at break of 15.5%, the CV value of the elongation at break of 7.0%, the central value of the elongation at 4.0cN/dtex load of 5.8%, the deviation rate of the elongation at 4.0cN/dtex load of 0.2%, the dry heat shrinkage rate under the conditions of 177 ℃ multiplied by 10min multiplied by 0.05cN/dtex of 8.3%, the network degree of 8/m, the oil content of 0.65 wt%, the light fastness of 7 level and the ultraviolet transmittance of 4.4%; the dye uptake under the temperature condition of 130 ℃ is 90.7 percent, and the K/S value is 25.10.

Example 4

(1) preparing modified polyester;

(1.1) synthesizing 2,2,5, 5-tetramethyl-3, 4-hexanediol by the following steps: firstly, mixing a 2, 2-methylpropionaldehyde solution with the concentration of 300g/L and a dilute sulfuric acid solution with the concentration of 250g/L according to the molar ratio of the 2, 2-methylpropionaldehyde to sulfuric acid of 1.8:1, adding the mixture into a cathode electrolytic cell, then cooling the mixed solution to 15 ℃, carrying out electrolytic reduction to the concentration of the 2, 2-methylpropionaldehyde of 9.3 wt%, and finally carrying out cooling crystallization, separation and purification, wherein a reaction device and a reaction chemical equation adopted in the synthesis process are consistent with those of example 1, and the structural formula of the prepared 2,2,5, 5-tetramethyl-3, 4-hexanediol is shown as a formula (I), wherein R is-H;

(1.2) preparing 3-trimethylsilyl-3-methyl-1, 2-propanediol;

(1.2.1) mixing 3-trimethylsilyl-3-methylpropene, peracetic acid and dichloromethane according to the molar ratio of 1:10:10, reacting for 6 hours at the temperature of 36 ℃, stirring during the reaction, removing the solvent after the reaction is finished, and purifying and refining to obtain trimethylsilyl propylene epoxide;

(1.2.2) mixing water, concentrated sulfuric acid and trimethylsilyl propylene epoxide, heating the mixture in water bath to 84 ℃ under the condition of stirring, preserving the heat for reaction for 12min, cooling the mixture to room temperature after the reaction is finished, and neutralizing, distilling, separating and purifying the mixture to obtain the 3-trimethylsilyl-3-methyl-1, 2-propylene glycol shown as the formula (II), wherein R in the formula (II) is-CH (CH)₃) -, concentrated sulfuric acid is 70% sulfuric acid by mass, and at the beginning of the reaction, trimethylsilyl propylene epoxide is addedThe molar ratio of the compound to the water is 1:30, and the mass of the concentrated sulfuric acid accounts for 0.14 percent of the mass sum of the mixture;

(1.3) esterification reaction;

preparing terephthalic acid, ethylene glycol, 3-trimethylsilyl-3-methyl-1, 2-propanediol and 2,2,5, 5-tetramethyl-3, 4-hexanediol with the molar ratio of 1:1.9:0.025:0.015 into slurry, adding zinc oxide powder, antimony acetate, titanium dioxide and triphenyl phosphate, uniformly mixing, pressurizing in a nitrogen atmosphere to perform esterification reaction, wherein the pressurizing pressure is 0.3MPa, the esterification reaction temperature is 254 ℃, the esterification reaction end point is the end point of the esterification reaction when the water distillate in the esterification reaction reaches 96% of a theoretical value, the adding amounts of the zinc oxide powder, the antimony acetate, the titanium dioxide and the triphenyl phosphate are respectively 0.3 wt%, 0.03 wt%, 0.25 wt% and 0.05 wt% of the adding amount of the terephthalic acid, and the average particle size of the zinc oxide powder is 0.25 micron;

(1.4) a polycondensation reaction;

after the esterification reaction is finished, starting the polycondensation reaction in the low vacuum stage under the negative pressure condition, stably pumping the pressure in the stage from normal pressure to the absolute pressure of 410Pa within 40min, controlling the reaction temperature to be 255 ℃ and the reaction time to be 32min, then continuing to pump vacuum, and carrying out the polycondensation reaction in the high vacuum stage to further reduce the reaction pressure to the absolute pressure of 95Pa, control the reaction temperature to be 275 ℃ and control the reaction time to be 70min, thus obtaining the modified polyester;

(1.5) carrying out solid phase polycondensation tackifying on the modified polyester to obtain a modified polyester melt with the intrinsic viscosity of 1.2 dL/g;

the technological parameters of stretching and heat setting are as follows:

the finally prepared polyester industrial yarn for the aerial work safety belt has the filament number of 10.4dtex, the multifilament number of 1450dtex, the breaking strength of 8.45cN/dtex, the deviation rate of linear density of-0.8%, the CV value of breaking strength of 2.6%, the elongation at break of 15.2%, the CV value of elongation at break of 7.1%, the central value of the elongation at 4.0cN/dtex load of 5.2%, the deviation rate of the elongation at 4.0cN/dtex load of 0.4%, the dry heat shrinkage rate under the conditions of 177 ℃ multiplied by 10min multiplied by 0.05cN/dtex of 8.0%, the network degree of 7/m, the oil content of 0.62 wt%, the light fastness of 7 level and the ultraviolet transmittance of 4.6%; the dye uptake under the temperature condition of 130 ℃ is 91.6 percent, and the K/S value is 25.50.

Example 5

(1) preparing modified polyester;

(1.1) synthesizing 2,2,5, 5-tetramethyl-3, 4-diethyl-3, 4-hexanediol by the following steps: firstly, mixing a 2, 2-dimethyl 3-pentanone solution with the concentration of 310g/L and a dilute sulfuric acid solution with the concentration of 300g/L according to the molar ratio of the 2, 2-dimethyl 3-pentanone to the sulfuric acid of 1.9:1, adding the mixture into a cathode electrolytic cell, then cooling the mixed solution to 15 ℃, then carrying out electrolytic reduction to the concentration of the 2, 2-dimethyl 3-pentanone of 8.8 wt%, and finally carrying out cooling crystallization, separation and purification, wherein a reaction device and a reaction chemical equation adopted in the synthetic process are consistent with those of example 1, and the structural formula of the prepared 2,2,5, 5-tetramethyl-3, 4-diethyl-3, 4-hexanediol is shown as a formula (I), wherein R is-CH (CH-CH) in the formula₂CH₃；

(1.2) preparing 3-trimethylsilyl-3, 3-dimethyl-1, 2-propanediol;

(1.2.1) mixing 3-trimethylsilyl-3, 3-dimethylpropene, peracetic acid and dichloromethane according to the molar ratio of 1:8:12, reacting for 5 hours at the temperature of 40 ℃, stirring during the reaction, removing the solvent after the reaction is finished, and purifying and refining to obtain trimethylsilyl propylene epoxide;

(1.2.2) mixing water, concentrated sulfuric acid and trimethylsilyl propylene epoxide, heating the mixture in water bath to 85 ℃ under the condition of stirring, preserving the heat for reaction for 10min, cooling the mixture to room temperature after the reaction is finished, and neutralizing, distilling, separating and purifying the mixture to obtain the 3-trimethylsilyl-3, 3-dimethyl-1, 2-propylene glycol shown as the formula (II) in which R is-C ((CH) in the formula (II)₃)₂) The concentrated sulfuric acid is sulfuric acid with the mass concentration of 70%, the molar ratio of the trimethylsilyl propylene epoxide to water is 1:25 when the reaction starts, and the mass of the concentrated sulfuric acid accounts for 0.12% of the mass sum of the mixture;

(1.3) esterification reaction;

preparing terephthalic acid, ethylene glycol, 3-trimethylsilyl-3, 3-dimethyl-1, 2-propanediol and 2,2,5, 5-tetramethyl-3, 4-diethyl-3, 4-hexanediol with the molar ratio of 1:2.0:0.024:0.016 into slurry, adding zinc oxide powder, ethylene glycol antimony, titanium dioxide and trimethyl phosphite, uniformly mixing, pressurizing in nitrogen atmosphere to perform esterification reaction at 0.2MPa and 256 deg.c, when the distilled amount of water in the esterification reaction reaches 99 percent of a theoretical value, the end point of the esterification reaction is defined, the adding amounts of zinc oxide powder, ethylene glycol antimony, titanium dioxide and trimethyl phosphite are respectively 0.5wt percent, 0.03wt percent, 0.20wt percent and 0.04wt percent of the adding amount of terephthalic acid, and the average grain diameter of the zinc oxide powder is 0.28 micron;

(1.4) a polycondensation reaction;

after the esterification reaction is finished, starting the polycondensation reaction in the low vacuum stage under the negative pressure condition, stably pumping the pressure in the stage from normal pressure to absolute pressure of 490Pa within 45min, controlling the reaction temperature to 257 ℃ and the reaction time to 40min, then continuing to pump vacuum, and carrying out the polycondensation reaction in the high vacuum stage to further reduce the reaction pressure to absolute pressure of 90Pa, control the reaction temperature to 277 ℃ and control the reaction time to 75min, thus obtaining the modified polyester;

(1.5) carrying out solid phase polycondensation tackifying on the modified polyester to obtain a modified polyester melt with the intrinsic viscosity of 1.05 dL/g;

the technological parameters of stretching and heat setting are as follows:

the finally prepared polyester industrial yarn for the aerial work safety belt has the filament number of 10.0dtex, the multifilament number of 1200dtex, the breaking strength of 8.8cN/dtex, the deviation rate of linear density of 1.2%, the CV value of the breaking strength of 2.5%, the elongation at break of 14.0%, the CV value of the elongation at break of 7.0%, the central value of the elongation at 4.0cN/dtex load of 5.7%, the deviation rate of the elongation at 4.0cN/dtex load of 0.5%, the dry heat shrinkage rate under the conditions of 177 ℃ multiplied by 10min multiplied by 0.05cN/dtex of 7.8%, the network degree of 5/m, the oil content of 0.55 wt%, the light fastness of 7 grade and the ultraviolet transmittance of 4.4%; the dye uptake under the temperature condition of 130 ℃ is 90.0 percent, and the K/S value is 24.85.

Example 6

(1) preparing modified polyester;

(1.1) synthesizing 2,2,4, 4-tetramethyl-3, 4-di-tert-butyl-3, 4-hexanediol by the following steps: firstly, mixing a 2,24, 4-tetramethyl-3-pentanone solution with the concentration of 350g/L and a dilute sulfuric acid solution with the concentration of 220g/L according to the molar ratio of 2,24, 4-tetramethyl-3-pentanone to sulfuric acid of 2:1, adding the mixture into a cathode electrolytic cell, then cooling the mixed solution to 13 ℃, carrying out electrolytic reduction until the concentration of the 2,24, 4-tetramethyl-3-pentanone is 9.6 wt%, and finally carrying out cooling crystallization, separation and purification, wherein a reaction device and a reaction chemical equation adopted in the synthetic process are consistent with those of example 1, and the structural formula of the prepared 2,2,4, 4-tetramethyl-3, 4-di-tert-butyl-3, 4-hexanediol is shown as a formula (I), wherein R is-C (CH)₃)₃；

(1.2) preparing 3-trimethylsilyl-3, 3-dimethyl-1, 2-propanediol;

(1.2.1) mixing 3-trimethylsilyl-3, 3-dimethylpropene, peracetic acid and dichloromethane according to the molar ratio of 1:10:10, reacting for 6 hours at the temperature of 35 ℃, stirring during the reaction, removing the solvent after the reaction is finished, and purifying and refining to obtain trimethylsilyl propylene epoxide;

(1.2.2) mixing water, concentrated sulfuric acid and trimethylsilyl propylene epoxide, heating the mixture in water bath to 80 ℃ under the condition of stirring, preserving the heat for reaction for 15min, cooling the mixture to room temperature after the reaction is finished, and neutralizing, distilling, separating and purifying the mixture to obtain the 3-trimethylsilyl-3, 3-dimethyl-1, 2-propylene glycol shown as the formula (II) in which R is-C ((CH) in the formula (II)₃)₂) The concentrated sulfuric acid is sulfuric acid with the mass concentration of 70%, the molar ratio of the trimethylsilyl propylene epoxide to water is 1:35 when the reaction starts, and the mass of the concentrated sulfuric acid accounts for 0.14% of the mass sum of the mixture;

(1.3) esterification reaction;

preparing terephthalic acid, ethylene glycol, 3-trimethylsilyl-3, 3-dimethyl-1, 2-propanediol and 2,2,4, 4-tetramethyl-3, 4-di-tert-butyl-3, 4-hexanediol with the molar ratio of 1:1.2:0.03:0.02 into slurry, adding zinc oxide powder, antimony trioxide, titanium dioxide and trimethyl phosphate, uniformly mixing, pressurizing in nitrogen atmosphere to perform esterification reaction at pressure of 0.2MPa and temperature of 258 ℃, when the distilled amount of water in the esterification reaction reaches 95 percent of a theoretical value, the end point of the esterification reaction is defined, the adding amounts of zinc oxide powder, antimony trioxide, titanium dioxide and trimethyl phosphate are respectively 0.4wt percent, 0.04wt percent, 0.23wt percent and 0.01wt percent of the adding amount of terephthalic acid, and the average grain diameter of the zinc oxide powder is 0.28 micron;

(1.4) a polycondensation reaction;

after the esterification reaction is finished, starting the polycondensation reaction in the low vacuum stage under the negative pressure condition, stably pumping the pressure in the stage from normal pressure to absolute pressure of 430Pa within 35min, the reaction temperature of 258 ℃ and the reaction time of 40min, then continuing to pump vacuum, and carrying out the polycondensation reaction in the high vacuum stage to further reduce the reaction pressure to absolute pressure of 94Pa, the reaction temperature of 280 ℃ and the reaction time of 80min to obtain the modified polyester;

the technological parameters of stretching and heat setting are as follows:

the finally prepared polyester industrial yarn for the aerial work safety belt has the filament number of 8.5dtex, the multifilament number of 1100dtex, the breaking strength of 8.1cN/dtex, the deviation rate of linear density of 1.5%, the CV value of the breaking strength of 3.0%, the elongation at break of 13.0%, the CV value of the elongation at break of 8.0%, the central value of the elongation at 4.0cN/dtex load of 4.8%, the deviation rate of the elongation at 4.0cN/dtex load of 0.8%, the dry heat shrinkage rate under the conditions of 177 ℃ multiplied by 10min multiplied by 0.05cN/dtex of 7.0%, the network degree of 3/m, the oil content of 0.4 wt%, the light fastness of 8 grade and the ultraviolet transmittance of 4.9%; the dye uptake under the temperature condition of 130 ℃ is 93.7 percent, and the K/S value is 26.56.

Example 7

(1) preparing modified polyester;

(1.1) synthesizing 2,2,5, 5-tetramethyl-3, 4-hexanediol by the following steps: firstly, mixing a 2, 2-methylpropionaldehyde solution with the concentration of 340g/L and a dilute sulfuric acid solution with the concentration of 260g/L according to the molar ratio of the 2, 2-methylpropionaldehyde to sulfuric acid of 1.5:1, adding the mixture into a cathode electrolytic cell, then cooling the mixed solution to 13 ℃, carrying out electrolytic reduction to the concentration of the 2, 2-methylpropionaldehyde of 9.5 wt%, and finally carrying out cooling crystallization, separation and purification, wherein a reaction device and a reaction chemical equation adopted in the synthesis process are consistent with those of example 1, and the structural formula of the prepared 2,2,5, 5-tetramethyl-3, 4-hexanediol is shown as a formula (I), wherein R is-H;

(1.2) preparing 3-trimethylsilyl-3, 3-dimethyl-1, 2-propanediol;

(1.2.1) mixing 3-trimethylsilyl-3, 3-dimethylpropene, peracetic acid and dichloromethane according to the molar ratio of 1:5:15, reacting for 7 hours at the temperature of 37 ℃, stirring during the reaction, removing the solvent after the reaction is finished, and purifying and refining to obtain trimethylsilyl propylene epoxide;

(1.2.2) mixing water, concentrated sulfuric acid and trimethylsilyl propylene epoxide, heating the mixture in water bath to 82 ℃ under the condition of stirring, preserving the heat for reaction for 12min, cooling the mixture to room temperature after the reaction is finished, and neutralizing, distilling, separating and purifying the mixture to obtain the 3-trimethylsilyl-3, 3-dimethyl-1, 2-propylene glycol shown as the formula (II) in which R is-C ((CH) in the formula (II)₃)₂) The concentrated sulfuric acid is sulfuric acid with the mass concentration of 70%, the molar ratio of the trimethylsilyl propylene epoxide to water is 1:29 when the reaction starts, and the mass of the concentrated sulfuric acid accounts for 0.13% of the mass sum of the mixture;

(1.3) esterification reaction;

preparing terephthalic acid, ethylene glycol, 3-trimethylsilyl-3, 3-dimethyl-1, 2-propanediol and 2,2,5, 5-tetramethyl-3, 4-hexanediol with the molar ratio of 1:2.0:0.03:0.02 into slurry, adding zinc oxide powder, ethylene glycol antimony, titanium dioxide and triphenyl phosphate, uniformly mixing, pressurizing in a nitrogen atmosphere to perform esterification reaction, wherein the pressurizing pressure is 0.3MPa, the esterification reaction temperature is 260 ℃, the esterification reaction end point is the water distillation amount reaching 91% of a theoretical value in the esterification reaction, the adding amounts of the zinc oxide powder, the ethylene glycol antimony, the titanium dioxide and the triphenyl phosphate are respectively 0.5 wt%, 0.05 wt%, 0.25 wt% and 0.05 wt% of the adding amount of the terephthalic acid, and the average particle size of the zinc oxide powder is 0.27 micrometers;

(1.4) a polycondensation reaction;

after the esterification reaction is finished, starting the polycondensation reaction in the low vacuum stage under the negative pressure condition, smoothly pumping the pressure in the stage from normal pressure to the absolute pressure of 400Pa within 50min, controlling the reaction temperature to be 260 ℃ and the reaction time to be 50min, then continuing to pump vacuum, and carrying out the polycondensation reaction in the high vacuum stage to further reduce the reaction pressure to the absolute pressure of 88Pa, control the reaction temperature to be 282 ℃ and control the reaction time to be 90min, thus obtaining the modified polyester;

(1.5) carrying out solid phase polycondensation tackifying on the modified polyester to obtain a modified polyester melt with the intrinsic viscosity of 1.15 dL/g;

the technological parameters of stretching and heat setting are as follows:

the finally prepared polyester industrial yarn for the aerial work safety belt has the filament number of 9.0dtex, the multifilament number of 1180dtex, the breaking strength of 8.15cN/dtex, the deviation rate of linear density of-1.5%, the breaking strength CV value of 2.9%, the elongation at break of 13.3%, the elongation at break CV value of 8.0%, the central value of the elongation at 4.0cN/dtex load of 4.85%, the deviation rate of the elongation at 4.0cN/dtex load of-0.8%, the dry heat shrinkage rate under the conditions of 177 ℃ multiplied by 10min multiplied by 0.05cN/dtex of 7.1%, the network degree of 4/m, the oil content of 0.5 wt%, the light fastness of 8 grade and the ultraviolet transmittance of 4.8 grade; the dye uptake under the temperature condition of 130 ℃ is 93.3 percent, and the K/S value is 26.42.

Claims

1. The preparation method of the polyester industrial yarn for the aerial work safety belt is characterized by comprising the following steps of: carrying out solid phase polycondensation tackifying, melting, metering, extruding, cooling, oiling, stretching, heat setting and winding on the modified polyester melt to obtain the polyester industrial yarn for the aerial work safety belt;

the molar ratio of the terephthalic acid to the dihydric alcohol with the trimethylsilyl lateral group to the hexanediol with the tert-butyl lateral group is 1: 0.02-0.03: 0.01-0.02;

in the formula (I), R is-CH₂-、-CH(CH₃) -or-C (CH)₃)₂-, in the formula (II), R is-H or-CH₂CH₃or-C (CH)₃)₃。

2. The method for preparing the polyester industrial yarn for the aerial work safety belt according to claim 1, wherein the synthesis steps of the diol with the trimethylsilyl group side group are as follows:

in the formula (I), R is-CH (CH)₃) -and-C (CH)₃)₂-when said starting alkenes correspond to 3-trimethylsilyl-3-methylpropene and 3-trimethylsilyl-3, 3-dimethylpropene;

in the formula (II), R is-H, -CH₂CH₃and-C (CH)₃)₃In this case, the raw material A is 2, 2-methylpropionaldehyde, 2-dimethyl-3-pentanone, and 2,2,4, 4-tetramethyl-3-pentanone, respectively.

3. The preparation method of the polyester industrial yarn for the aerial work safety belt according to claim 2, wherein the preparation steps of the modified polyester before solid-phase polycondensation and tackifying are as follows:

(1) performing esterification reaction;

(2) performing polycondensation reaction;

4. The preparation method of the polyester industrial yarn for the aerial work safety belt as claimed in claim 3, wherein the molar ratio of the terephthalic acid to the ethylene glycol is 1: 1.2-2.0, and the addition amounts of the zinc oxide powder, the catalyst, the delustering agent and the stabilizer are 0.3-0.5 wt%, 0.03-0.05 wt%, 0.20-0.25 wt% and 0.01-0.05 wt% of the addition amount of the terephthalic acid, respectively.

5. The method for preparing the industrial polyester yarn for the aerial work safety belt according to claim 4, wherein the catalyst is antimony trioxide, ethylene glycol antimony or antimony acetate, the delustrant is titanium dioxide, and the stabilizer is triphenyl phosphate, trimethyl phosphate or trimethyl phosphite.

6. The preparation method of the industrial polyester yarn for the aerial work safety belt according to claim 1, wherein the intrinsic viscosity of the modified polyester after solid phase polycondensation and tackifying is 1.0-1.2 dL/g.

7. The preparation method of the polyester industrial yarn for the aerial work safety belt according to claim 1, wherein the spinning process parameters of the polyester industrial yarn for the aerial work safety belt are as follows:

the technological parameters of stretching and heat setting are as follows:

8. the polyester industrial yarn for the safety belt for the aerial work, which is prepared by the preparation method of the polyester industrial yarn for the safety belt for the aerial work according to any one of claims 1 to 7, is characterized in that: the material is modified polyester;

9. The industrial polyester yarn for the aerial work safety belt according to claim 8, wherein the industrial polyester yarn for the aerial work safety belt has a single-filament fineness of 8.5 to 12.5dtex, a multifilament fineness of 1100 to 1700dtex, a breaking strength of 8.1cN/dtex or more, a deviation rate of linear density of ± 1.5%, a CV value of breaking strength of 3.0% or less, an elongation at break of 13.0 to 16.5%, a CV value of elongation at break of 8.0% or less, a central value of elongation of 4.0cN/dtex load of 4.8 to 6.3%, a deviation rate of elongation of 4.0cN/dtex load of ± 0.8%, a dry heat shrinkage rate of 7.0 to 9.5% under 177 ℃ x 10min x 0.05cN/dtex conditions, a network degree of (5 to 8) ± 2/m, and an oil content of 0.6 ± 0.2 wt%.

10. The polyester industrial yarn for the aerial work safety belt according to claim 8, wherein the polyester industrial yarn for the aerial work safety belt has a light fastness of 7 to 8 grade, an ultraviolet transmittance of less than 5%, a dyeing rate of 88.4 to 93.7% at a temperature of 130 ℃, and a K/S value of 24.24 to 26.56.