CN113087897B

CN113087897B - Polyester amide and its preparation method and fiber

Info

Publication number: CN113087897B
Application number: CN201911334232.XA
Authority: CN
Inventors: 杜宇鎏; 刘修才
Original assignee: Cathay R&D Center Co Ltd; CIBT America Inc
Current assignee: Cathay R&D Center Co Ltd; CIBT America Inc
Priority date: 2019-12-23
Filing date: 2019-12-23
Publication date: 2023-11-17
Anticipated expiration: 2039-12-23
Also published as: CN113087897A

Abstract

The invention provides a polyester amide, a preparation method thereof and fibers. The preparation method of the polyester amide comprises the steps of adding an antioxidant, and introducing nylon salt in the form of an deoxidized aqueous solution after the esterification reaction is finished, so that the problem of serious yellowing in the polyester amide synthesis process is solved, and the obtained polyester amide has a lower yellow index. The fiber prepared from the polyester amide has higher breaking strength and good breaking elongation.

Description

Polyester amide, preparation method thereof and fiber

Technical Field

The invention belongs to the field of high polymer materials, and particularly relates to a polyester amide, a preparation method thereof and fibers, in particular to a yellowing-resistant polyester amide resin material, a preparation process thereof and fibers prepared from the polyester amide.

Background

Polyester amides are a class of copolymers containing ester and amide linkages in the molecular backbone. Due to the structural specificity, the polyester amide has the advantages of polyester and polyamide to a certain extent. In addition, the cost is low, so the polyester amide is widely applied to various fields such as fibers, biodegradable materials, plastic films and the like.

In the fiber field of the present stage, polyester amide is generally obtained by firstly reacting diamine and diacid to generate an intermediate containing an amide bond and then polycondensing the intermediate with dihydric alcohol; or is obtained by esterification and acylation reaction of dihydric alcohol, terephthalic acid and/or derivatives thereof and nylon salt, and polycondensation reaction. However, in the polymerization production process, as a certain amount of aldehyde byproducts are produced in the esterification and polycondensation processes of the dihydric alcohol, side reactions are generated with the amino groups in the products, and byproducts containing conjugated chromophore groups are generated, so that serious yellowing of the products is caused, and the performance and quality of the products are affected. Therefore, developing a process for preparing polyesteramide which can inhibit yellowing problem in the reaction process, and producing high quality polyesteramide products is a problem to be solved by those skilled in the fiber field.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a preparation method of polyester amide, which can greatly improve the yellowing problem in the synthesis process of the polyester amide and obtain the yellowing-resistant polyester amide.

The invention also aims to provide the polyester amide which is prepared by adopting the preparation method, so that the polyester amide has a lower yellow index, and the mechanical property of the polyester amide can be kept at a good level.

The invention also aims to provide a fiber which is prepared from the polyester amide as a raw material and has high-quality mechanical and dyeing properties.

In order to achieve the above object, the present invention provides a method for preparing a polyesteramide, comprising the steps of:

1) In an inert atmosphere, carrying out esterification reaction on terephthalic acid and/or derivatives thereof and dihydric alcohol in the presence of a catalyst in an esterification reaction kettle;

2) After the esterification reaction is finished, adding a nylon salt water solution prepared by deoxidized water into the esterification reaction kettle for reaction, wherein the mass concentration of the nylon salt water solution is 20-80%;

3) After the reaction of the step 2), transferring the product obtained in the step 2) into a polycondensation reaction kettle for polycondensation, and ending the polycondensation reaction when the intrinsic viscosity of the polycondensation product reaches 0.3-1.8 dL/g to obtain the polyesteramide.

In some preferred embodiments of the present invention, an antioxidant is further added in step 1), and the antioxidant used may be specifically selected from commercially available antioxidants including hindered phenol antioxidant 1010, antioxidant 1076, antioxidant 1098, antioxidant 3114, antioxidant 245, antioxidant GA-80, and one or more of phosphite antioxidant 168, antioxidant THP-24, and the like, and is not limited to the mentioned types, but is more preferably one or more of antioxidant 1010, antioxidant 1076, antioxidant 168, and antioxidant THP-24.

The polyester amide is easy to decompose under heating to cause yellowing, and proper antioxidants are selected to help reduce the occurrence of decomposition, so that the occurrence of yellowing of the polyester amide is avoided. The common decomposition types of polyesteramides are mainly thermal degradation and thermal oxidative degradation. Aiming at the occurrence of thermal degradation, phosphoric acid, phosphorous acid and esters thereof can act with a metal catalyst for promoting the thermal degradation to generate metal phosphate compounds, reduce the activity of catalyst metal, improve the stability of polyester amide products, and simultaneously, the phosphite antioxidant can promote the decomposition of peroxide generated in the production process of the polyester amide, thereby further improving the stability of the products. Aiming at the occurrence of thermal oxygen degradation, the main antioxidant effect of the hindered phenol antioxidant is that the hindered phenol antioxidant has a molecular active-OH functional group, and peroxy free radicals participating in side reactions can be captured through hydrogen transfer, so that the occurrence of the side reactions is prevented.

The mass ratio of the antioxidant addition amount to the total mass of the polyesteramide is 3000ppm or less, preferably 20 to 3000ppm.

In the invention, the adding amount of the antioxidant is generally measured by the mass of the antioxidant relative to the theoretical polyester amide product, and the using amount is different according to different types of the antioxidant. Specifically, when the antioxidant 1010 or the antioxidant 1076 is used, the mass ratio of the antioxidant to the theoretical yield of the polyesteramide is 20 to 3000ppm, preferably 100 to 1500ppm, and more preferably 200 to 1000ppm.

According to a preferred technical scheme provided by the invention, a certain amount of antioxidant is added into a reaction system before the esterification reaction, then a nylon salt aqueous solution prepared by deoxidized water with a specific mass concentration is added for reaction, and then polycondensation is carried out, so that the obtained polyester amide has a very low yellow index. The inventors analyzed based on this phenomenon to believe that it may be due to: the proper antioxidant can effectively capture peroxidation free radicals generated in the reaction process, and prevent the polymer from being further oxidized to generate chromophore; after the esterification reaction is finished, nylon salt is introduced in a nylon salt aqueous solution mode, so that the dispersity of the nylon salt in a reaction system is better, and the yellowing of the polyester amide is reduced. Meanwhile, the salt solution prepared by using the deoxidized water further avoids the introduction of oxygen in a system, further inhibits the side reaction of converting dihydric alcohol into aldehyde compounds, and further avoids the generation of compounds containing conjugate groups which cause yellowing due to the further oxidation reaction of raw materials and the aldehyde compounds, thereby effectively avoiding the yellowing problem of polyester amide.

The dihydric alcohol is not particularly limited, and can be dihydric alcohol raw materials commonly used for synthesizing polyester amide at present, such as aliphatic dihydric alcohol with a carbon chain length of 2-18, and the molecular structural formula can be expressed as follows:

Wherein x is an integer of 2 to 18. Preferably, x is an integer from 2 to 4, such as x is 2, i.e., ethylene Glycol (EG).

The present invention is not particularly limited either, and may be one or more of terephthalic acid and/or its derivatives conventionally used in the synthesis of polyester amides, such as terephthalic acid, or a compound in which hydrogen on the benzene ring of terephthalic acid is substituted in whole or in part by an alkane having 1 to 4 carbon atoms. The molecular structural formula of terephthalic acid and/or its derivatives can be represented as follows:

wherein R is ₁ ～R ₄ Independently selected from H, C ₁ ～C ₄ One of the alkyl groups, e.g. R ₁ ～R ₄ Are all H, i.e. terephthalic acid (PTA))。

The process conditions of the esterification reaction are not particularly limited, and the process conditions can be conventional processes of the esterification reaction step in the prior art for synthesizing the polyester amide, and can be reasonably determined according to the types of the used raw materials. In the specific implementation process of the invention, dihydric alcohol, terephthalic acid and/or derivatives thereof and a catalyst are added into an esterification reaction kettle under the protection of nitrogen or inert gas and are stirred uniformly, the temperature in the esterification reaction kettle is controlled to be increased to 230-280 ℃, preferably 240-270 ℃, more preferably 250-265 ℃, and in the esterification reaction process, the esterification reaction product is fractionated by a fractionating tower, and low boiling components such as water are continuously fractionated, so as to promote the smooth progress of the esterification reaction, and the completion of the esterification reaction can be judged by the distilled water. The fractionation temperature is generally based on the top temperature of the fractionation column, and the top temperature of the fractionation column is generally controlled to 145 to 155 ℃.

The end of the esterification reaction in the present invention is determined by following the general standard in the art of polyester synthesis, that is, when 90% or more of terephthalic acid and/or its derivatives undergo esterification, the end of the esterification reaction can be regarded as an end of the esterification reaction. In the implementation process of the invention, the reaction completion rate of terephthalic acid and/or the derivative thereof in the esterification stage is generally controlled to be more than 95 percent, for example, the distilled water amount reaches 95 to 98 percent of the theoretical amount, and the esterification reaction can be regarded as being completed. It will be appreciated that the higher the ratio of esterification, the more advantageous the subsequent polycondensation reaction proceeds.

In the invention, the catalyst used in the preparation process of the polyesteramide can be reasonably selected according to the actual reaction condition, the used raw materials and other factors. Wherein, in the esterification reaction stage, an ester exchange catalyst and/or an esterification catalyst can be optionally added, and in addition, an etherification catalyst, an etherification inhibitor and the like can be added according to actual requirements. In the polycondensation reaction stage, a polymerization catalyst, a polymerization regulator, and the like may be added.

The transesterification catalyst and the esterification catalyst may be transesterification catalysts and esterification catalysts commonly used in the art for polyester synthesis, for example, compounds containing manganese, cobalt, zinc, titanium, calcium, and the like.

The etherification inhibitor may be an etherification inhibitor commonly used in the art, such as an amine compound.

The polymerization catalyst may specifically be at least one of a germanium-containing catalyst, an antimony-containing catalyst, a titanium-containing catalyst, an aluminum-containing catalyst, an alkali metal-containing catalyst, and an alkaline earth metal-containing catalyst, wherein:

germanium-containing catalysts include, but are not limited to, germanium dioxide (including amorphous germanium dioxide, crystalline germanium dioxide), germanium chloride, tetraethoxygermanium, tetra-n-butoxygermane, and the like. The mass ratio between the germanium-containing catalyst and the theoretical yield of polyesteramide is 5 to 150ppm, preferably 10 to 100ppm, more preferably 20 to 70ppm, based on germanium atom; alternatively, the ratio of the mass of germanium atoms in the germanium-containing catalyst to the theoretical yield of polyesteramide is 5 to 150ppm, preferably 10 to 100ppm, more preferably 20 to 70ppm.

Antimony-containing catalysts include, but are not limited to, one or more of antimony trioxide, antimony pentoxide, antimony oxychloride, antimony acetate, antimony tartrate, potassium antimony tartrate, ethylene glycol antimony, triphenylantimony, and the like. The amount of the antimony-containing catalyst to be used may be generally 10 to 400ppm, preferably 20 to 300ppm, more preferably 30 to 250ppm, in terms of mass of antimony atoms, specifically, the mass ratio between the antimony atoms in the antimony-containing catalyst and the theoretical yield of the polyesteramide.

The titanium-containing catalyst includes, but is not limited to, at least one of tetraalkyl titanates and partial hydrolysates thereof, titanium oxalate salts, titanium sulfate, titanium tetrachloride, and the like. The tetraalkyl titanate can be, for example, tetraethyl titanate, tetraisopropyl titanate, tetra-n-propyl titanate, tetra-n-butyl titanate; the titanium oxalate may be, for example, titanium ammonium oxalate, titanium sodium oxalate, titanium potassium oxalate, titanium calcium oxalate, titanium strontium oxalate, or the like. The titanium-containing catalyst may be used in an amount of 0.5 to 300ppm, preferably 1 to 150ppm, more preferably 3 to 100ppm, by mass based on the mass of titanium atoms, specifically, the mass ratio between titanium atoms in the titanium-containing catalyst and the theoretical yield of polyesteramide.

The aluminum-containing catalyst may be at least one of an organoaluminum compound such as at least one of aluminum carboxylate, aluminum alkoxide, aluminum acetylacetonate, aluminum acetoacetate, trimethylaluminum, triethylaluminum, and the like, a partial hydrolysate of the organoaluminum compound, and an inorganic aluminum compound. The aluminum carboxylate compound may be, for example, aluminum formate, aluminum acetate, aluminum propionate, aluminum oxalate, or the like; the inorganic aluminum compound may be, for example, alumina, aluminum hydroxide, aluminum chloride, aluminum carbonate; the aluminum alkoxide may be, for example, aluminum methoxide, aluminum ethoxide, or the like. In addition, the aluminum-containing catalyst can also be complex compounds such as aluminum acetylacetonate, aluminum acetoacetate and the like, and organic aluminum compounds such as trimethylaluminum, triethylaluminum and the like and partial hydrolysis products thereof. The amount of the aluminum-containing catalyst to be used may be measured in terms of the mass of aluminum, and specifically, the mass ratio between the aluminum atom in the aluminum-containing catalyst and the theoretical yield of polyesteramide may be 1 to 400ppm, preferably 3 to 300ppm, more preferably 5 to 500ppm.

In comparison, when an antimony-containing catalyst is used, particularly when ethylene glycol antimony is used as the polymerization catalyst, the polycondensation reaction can proceed more stably, and the polyester amide has better properties, particularly a lower yellow index.

In the step 2), nylon salt is adopted as a raw material in the synthesis process of the polyester amide, and the nylon salt is formed by dibasic acid and diamine, so as to ensure that the dibasic acid and the diamine which participate in the reaction are basically in equimolar ratio. The diamine can be aliphatic diamine with carbon chain length of 2-18, and the molecular structural formula can be expressed as follows:

wherein y is an integer of 2 to 18, preferably an integer of 4 to 12, such as pentylene diamine, hexylene diamine, etc.;

the dibasic acid can be aliphatic dibasic acid with carbon chain length of 4-20, and the molecular structural formula can be expressed as follows:

wherein z is an integer from 2 to 18, preferably an integer from 3 to 6, such as glutaric acid, adipic acid.

In the present invention, the molar ratio between the nylon salt, the diol, the terephthalic acid and/or the derivative thereof can be generally controlled to be (0.002-99): 1-3): 1.

The reasonable control of the ratio of the dihydric alcohol to the terephthalic acid and/or the derivative thereof is beneficial to ensuring the complete esterification reaction, and in addition, the ratio of the flexible groups to the rigid groups in the molecular chain of the polyester amide is directly influenced so as to influence the performance of the polyester amide, and in some preferred embodiments of the invention, the molar ratio of the dihydric alcohol to the terephthalic acid and/or the derivative thereof is generally controlled to be (1.1-2.6): 1, preferably (1.2-2.0): 1.

The inventors have further studied and found that the amount of nylon salt added also affects the yellowness index of the polyesteramide, and that, in general, within a certain range, as the amount of nylon salt increases, the yellowness index of the polyesteramide increases. In the practice of the present invention, the molar ratio between the nylon salt and terephthalic acid and/or its derivatives is generally controlled to be (0.005-3): 1, preferably (0.01-0.3): 1, and more preferably (0.015-0.25): 1.

The source of the nylon salt raw material is not particularly limited, and the nylon salt can be purchased commercially or prepared by self, for example, the nylon salt can be prepared by neutralizing dibasic acid and diamine in solvents such as ethanol, water and the like through acid-base neutralization reaction.

In a preferred technical scheme of the invention, in the step 2), the nylon salt aqueous solution prepared by deoxidizing water is a solution prepared by dissolving nylon salt in deoxidizing water, and the deoxidizing water is water subjected to deoxidizing treatment. The oxygen scavenging water has a dissolved oxygen content of less than 0.2mg/L, preferably less than 0.1mg/L, more preferably less than 0.05mg/L, at 25℃and 1 normal atmospheric pressure.

Preferably, the raw material of the deoxidized water is desalted water, pure water or ultrapure water.

The deoxidization treatment is selected from one or a combination of a plurality of ultrasonic deoxidization, thermal deoxidization, vacuum deoxidization, chemical deoxidization, analytical deoxidization or other arbitrary deoxidization modes,

the ultrasonic deoxygenation is to carry out ultrasonic treatment on water so as to remove molecular oxygen in the water; the ultrasonic deoxygenation is preferably performed under an inert gas blanket, which may be nitrogen, argon, helium, xenon or mixtures thereof, especially nitrogen, argon or mixtures thereof.

The method is usually adopted, wherein nitrogen is introduced into pure water in a closed container under the protection of nitrogen by utilizing the characteristic that the solubility of gas is close to zero when water is in a boiling state, ultrasonic vibration is applied to the closed container, and a gas outlet pipeline is arranged, so that inert gas replaces the dissolved oxygen in the water by the introduced nitrogen under the action of ultrasonic waves. The ultrasonic vibration and the nitrogen introduction can be started simultaneously or can be started sequentially, and preferably the ultrasonic vibration and the nitrogen introduction are started simultaneously.

The ultrasonic deoxygenation can set the technological parameters of temperature, pressure, speed of inert gas, frequency and time of ultrasonic deoxygenation and the like according to the amount of water to be treated and the size of the container.

According to a preferred embodiment of the invention, the frequency of the ultrasound is selected from the group consisting of 25kHz to 1MHz, preferably 20kHz to 80kHz, and more preferably 20kHz to 60kHz.

According to a preferred technical scheme of the invention, the inert gas is used for preparing the catalyst with the particle size of 0.1-50 m ³ Gas/hour/m ³ The water is introduced at a rate of preferably 1 to 20m ³ Gas/hour/m ³ Water;

according to a preferred technical scheme, the deoxidization time is 10-120 min, further 30-80 min, and more preferably 40-60 min;

for example, for 10L of water to be treated at normal temperature and pressure, ultrasonic frequency of 35KHz is adopted, ultrasonic vibration and nitrogen gas introduction are started simultaneously, and the deoxidization time is 30-100 min, preferably 50-60 min.

The thermal deoxidization is to deoxidize water by low-pressure heat, namely, pure water is heated to the boiling point under the protection of nitrogen, so that dissolved oxygen in the water is reduced, overflowed oxygen is discharged together with water vapor, deoxidized water is obtained, and other gas impurities such as free nitrogen dioxide in the water can be discharged. Thermal deoxygenation is the removal of dissolved oxygen from water in deoxygenators by heating and stripping methods according to the principle that the solubility of gases decreases with increasing temperature. The working principle of the thermal deaerator is based on henry's law, dalton's law and heat and mass transfer law, the solubility of gas in liquid is proportional to partial pressure and inversely proportional to temperature. Therefore, the deoxidized water obtained after thermal deoxidization does not increase the salt content and other gas contents.

In a preferred embodiment of the present invention, the thermal deoxygenation is selected from the group consisting of atmospheric thermal deoxygenation and jet thermal deoxygenation.

In a preferred embodiment of the present invention, the thermal deoxidization is deoxidization by using a thermal atmospheric deoxidizer, for example, the thermal deoxidization is that the treated pure water and the steam condensate recovered by the production device are converged and then enter the deoxidizer, the deoxidization is heated by low-pressure steam from a low-pressure steam main pipe, and the water vapor carries dissolved oxygen to be discharged through a pipeline. Deoxygenated water is pumped through boiler feedwater to the reaction unit. The thermal deoxygenation can set technological parameters such as temperature, pressure, time and the like of deoxygenation according to the amount of water to be treated and the size of the container. In a preferred embodiment, the low pressure steam pressure during the deoxygenation reaction is between 0.02 and 0.06MPa, and the temperature is between 99 and 108 ℃, preferably about 105 ℃, and the internal pressure of the deoxygenator is between about 0.2 and 0.5MPa. The liquid level of water in the high-pressure thermodynamic container is 40-60%.

The chemical oxygen removal may be performed by adding a reducing agent to water, including, but not limited to, metal oxygen scavengers such as copper dust, scrap iron, etc.; inorganic salt deoxidizers such as sodium sulfite and the like; organic oxygen scavengers such as hydrazine (hydrazine). The addition amount of the reducing agent is 0.01 to 0.5% by weight of water, preferably 0.05 to 0.2%.

The chemical deoxidizing treatment can also be to remove oxygen in water through a redox resin deoxidizer.

In a preferred embodiment of the invention, the redox resin deaerator is a floating bed redox resin deaerator, and is filled with 95% of spherical sulfonated phenolic resin copper hydroxyl coordination catalytic redox resin or Y-12-06 type redox resin.

In the specific implementation process of the invention, nylon salt is dissolved in deoxidized water under the protection of nitrogen, and then the deoxidized aqueous solution of the nylon salt can be obtained. Of course, heating may be appropriate in order to obtain a relatively high mass concentration of the nylon salt aqueous solution. For example, when the mass concentration of the aqueous solution of the pentanediamine-adipic acid is lower than 50%, the pentanediamine-adipic acid salt can be fully dissolved by stirring at normal temperature, when the required mass concentration is 50% -80%, the aqueous solution can be properly heated, for example, heated to 60 ℃ and stirred for dissolution, and the prepared aqueous solution of the nylon salt needs to be added into an esterification reaction kettle for reaction when the aqueous solution of the nylon salt is hot.

After the esterification reaction is completed, a nylon salt aqueous solution is added into the esterification reaction kettle, and then the amidation reaction is started. Specifically, the nylon salt aqueous solution is added into the esterification reaction kettle through a charging tank under the protection of nitrogen or inert gas and is continuously stirred. The temperature in the esterification reaction kettle is controlled to be 255-265 ℃ in the amidation reaction process, and when the newly distilled water quantity is observed to be more than 60% of the total quantity of water produced by theoretical amidation and solvent water in nylon salt water solution, the stage can be considered to be completed. Typically, after adding the aqueous nylon salt solution, the amount of water distilled off again after about 10 minutes or more, such as 10 to 20 minutes, is 60 to 70% of the sum of the water produced by theoretical amidation and the water of the solvent in the aqueous nylon salt solution.

In some preferred technical schemes of the invention, in the step 3), after the reaction of the step 2), the reaction product is transferred into a polycondensation reaction kettle under the protection of nitrogen or inert gas for polycondensation reaction, and the intrinsic viscosity [ eta ] (intrinsic viscosity) of the polycondensation product to be measured reaches 0.3-1.8 dL/g, for example, 0.4-1.5 dL/g, so that the polycondensation reaction can be finished.

In some embodiments of the invention, the polycondensation reaction is carried out at a temperature of 230 to 310 ℃, preferably 240 to 280 ℃, more preferably 255 to 270 ℃.

Further, the polycondensation reaction may be specifically carried out in two stages, specifically, the pressure in the polycondensation reaction vessel is first reduced to 0.5 to 2kpa, after about 40 to 90 minutes of pre-polycondensation, and then reduced to 30Pa or less, preferably 10Pa or less, until the intrinsic viscosity of the polycondensation product reaches 0.3 to 1.8dL/g.

In the implementation process of the invention, the initial pressure in the polycondensation reaction kettle is generally controlled to be about 1kPa, and the pre-polycondensation can be completed after about 1 hour.

Additives may also be added to the esterification reactor prior to the polycondensation reaction described above. Specifically, before the esterification reaction starts, an additive may be added into the esterification reaction kettle; and/or, adding an additive to the esterification reaction vessel prior to transferring the amidated product to the polycondensation reaction vessel.

The invention is not particularly limited in the selection of the additive, and suitable additives can be selected and added according to the actual requirements on the properties of the polyesteramide product, and the additives include at least one of weather-resistant agents, anti-sticking agents, lubricants, crystallization nucleating agents, plasticizers, antistatic agents, flame retardants, fillers, heat stabilizers, light stabilizers and the like besides antioxidants. In addition, conductive materials and the like can be added to further improve the application performance of the polyesteramide product.

The above-mentioned additive may be added according to actual requirements without damaging the properties of the polyester amide product, and the manner of adding the above-mentioned additive may be by conventional known methods, and is not particularly limited herein.

Preferably, the additive used comprises at least a heat stabilizer, which may be chosen in particular from phosphoric acid, phosphorous acid (H) ₃ PO ₃ ) One or more of phosphorous compounds such as hypophosphorous acid compounds, phosphate compounds, phosphite compounds, phosphine compounds and derivatives thereof. By adding a heat stabilizer to the esterification reactor, it is advantageous to have a lower yellow index of the resulting polyesteramide.

Wherein the phosphate is esterified The compound belongs to orthophosphoric acid derivatives, and can be trimethyl phosphate, triethyl phosphate, tributyl phosphate, triphenyl phosphate, dimethyl phosphate, dibutyl phosphate, triethyl phosphonoacetate and the like. The hypophosphorous acid compound may be hypophosphorous acid (H) ₃ PO ₂ ) Hypophosphite such as sodium hypophosphite. The phosphite compound may be, for example, triethyl phosphite, tributyl phosphite, or the like. The phosphine compound and its derivative may be, for example, methylphosphonic acid dimethyl ester, ethylphosphonic acid dimethyl ester, phenylphosphonic acid diethyl ester, phenylphosphonic acid diphenyl ester, etc. In particular, when trimethyl phosphate is selected as the heat stabilizer, the resulting polyesteramide has a lower yellow index.

In the present invention, the amount of the heat stabilizer to be added is generally measured in terms of the mass of the phosphorus atom contained therein, specifically, the mass ratio between the phosphorus atom and the theoretical yield of the polyesteramide in the heat stabilizer is 1 to 200ppm, preferably 5 to 150ppm, and more preferably 10 to 100ppm.

And after the polycondensation reaction is finished, discharging, cooling the polycondensation product by pure water at 10 ℃, washing, drawing wires, and granulating to obtain the polyesteramide product.

The esterification reaction vessel and the polycondensation reaction vessel are all reaction vessels commonly used in the current polyester amide synthesis process, and the invention is not particularly limited. In the laboratory stage, as small-sized reaction equipment is adopted, only a single kettle is used, and esterification, amidation and polycondensation can be completed in one reaction kettle; in pilot plant or industrial production, a large-scale production device is adopted, for example, a pilot plant usually adopts the configuration of one esterification reaction kettle and one polycondensation reaction kettle, and in industrial production, a four-kettle system of two esterification reaction kettles and two polycondensation reaction kettles is usually adopted, so that after the esterification reaction kettle and the amidation reaction are completed, the reaction kettle can be transferred into the polycondensation reaction kettle for polycondensation reaction.

The invention also provides a polyester amide which is prepared by adopting the preparation method. As described above, by adding a specific antioxidant and introducing nylon salt in the form of an oxygen-scavenging aqueous solution after the esterification reaction is completed, the problem of serious yellowing frequently occurring in the polyester amide synthesis process at the present stage can be solved, so that the obtained polyester amide has a lower yellow index.

The invention also provides a fiber which is prepared from the polyester amide as a raw material.

The fiber product can be specifically polyester amide nascent fiber, polyester amide fiber filament, polyester amide POY fiber, polyester amide textured yarn, polyester amide FDY, polyester fiber staple fiber and the like.

The invention is not particularly limited to the specific processing technology of the fiber, and the fiber can be prepared by adopting the fiber processing technology at the present stage.

According to the preparation method of the polyesteramide, the antioxidant is added, so that free radicals and peroxy free radicals generated in the chain reaction stage can be captured, the chain reaction with destructive effect cannot be caused, meanwhile, the antioxidant can decompose peroxide to generate stable inactive products, and side reactions are inhibited. And by introducing nylon salt in an anaerobic aqueous solution mode after the esterification reaction is finished, the thermal oxygen degradation reaction caused by the existence of trace oxygen can be reduced, and the yellowing problem of the product is further improved. The two process improvements can effectively solve the yellowing problem in the current polyester amide synthesis process, obviously reduce the yellow index of the polyester amide, improve the thermal stability of the polyester amide and ensure other properties of the polyester amide. In addition, the preparation method is simple in process, and can be put into use by simple modification on the basis of the current polyester production device.

The fiber provided by the invention is prepared from the polyester amide as a raw material. Compared with the fiber product prepared by the polyesteramide obtained by the prior art, the fiber product provided by the invention has higher breaking strength and good elongation at break, so that the fiber product has more outstanding service performance. In addition, the fiber product provided by the invention has higher dye-uptake, thereby improving the processing performance of the fiber product. Thus, the present invention provides a fiber product with better overall properties.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Pentanediamine-adipate was obtained by the process described in reference patent CN105777553A, with a purity of more than 99%. Other raw materials and reagents such as terephthalic acid, ethylene glycol antimony and the like can be prepared by methods known in the literature or can be obtained commercially.

Example 1

The pure water was deoxygenated by ultrasonic waves, i.e., 1L of pure water was added to a 2L flask, and the flask was placed in an ultrasonic apparatus (model UC-10, frequency 35kHz, available from Tatany Corp.) to which water was added, the water surface of the ultrasonic apparatus exceeded the water surface in the flask. Firstly, starting an ultrasonic instrument, then vacuumizing the interior of the flask, keeping the flask for 3-5 minutes, then filling nitrogen to normal pressure, and then repeatedly pumping and filling air for 3-5 times again, and then, filling nitrogen to normal pressure. And (3) inserting a long needle tube into the position below the water surface, blowing nitrogen with the flow of 5L/h, guiding out nitrogen through another needle tube above the water surface, closing the ultrasound after keeping the nitrogen in the ultrasound on state for 1 hour, stopping introducing the nitrogen, and sealing and preserving. The oxygen-scavenging pure water sample was taken through a needle tube, and oxygen content was measured using a MetretolidoFiveGo F4 oxygen dissolving apparatus, which showed that the oxygen content in the oxygen-scavenging pure water was 0.02mg/L.

480g of pentylene diamine adipate prepared according to the method described in patent CN105777553A is added into a batching tank, the batching tank is vacuumized, and then nitrogen is introduced for three times for replacement, so that oxygen isolation is ensured. And transferring the deoxidized pure water obtained by the preparation into a batching tank, preparing an aqueous solution of pentanediamine-adipate with the mass concentration of 70%, and preserving nitrogen for later use.

Under the protection of nitrogen, adding 16.0kg of terephthalic acid and 7.48kg of ethylene glycol into a 100L esterification reaction kettle, adding 7.8g of ethylene glycol antimony catalyst, heating to about 260 ℃ for reaction, fractionating low-boiling components, and ending the esterification reaction when the low-boiling components reach 98% of theoretical amount after the reaction is carried out for about 300 minutes.

To the esterification reactor, 4.86g of trimethyl phosphate as a stabilizer was added, and the aqueous solution of pentamethylenediamine-adipic acid salt prepared by the above deoxidized pure water was further added, followed by stirring at about 260℃for about 10 minutes. And transferring the materials in the esterification reaction kettle to a polycondensation reaction kettle under the protection of nitrogen, heating to 280 ℃, vacuumizing to 1kPa, reacting for about 1 hour, switching a high vacuum pump, vacuumizing to below 30Pa, and continuously reacting at the temperature for 1 hour and 55 minutes. When the stirring current reaches 0.61A, 0.3MPa nitrogen is filled into the polymerization reaction kettle, and the mixture is subjected to wiredrawing and granulating.

Example 2

Adding pure water into the preparation tank, firstly turning on ultrasonic, then pumping the interior of the preparation tank to vacuum of-0.03 MPa (gauge pressure), holding for 13-15 min, and standing for 20m ³ /h/m ³ And (3) filling nitrogen into the water at the speed of normal pressure, and then repeatedly pumping and filling air for 3-5 times, and then, filling nitrogen to restore the normal pressure. Introducing nitrogen into water via the conduit, guiding out via the conduit of the device, and maintaining at ultrasonic open state for 50m ³ The rate of/h was purged with nitrogen for 1 hour, followed by the ultrasound and nitrogen being turned off. The measurement was carried out using the measurement method described in example 1, and the result showed that the oxygen content in the deoxygenated water was measured to be 0.03mg/L.

480g of pentylene diamine adipate prepared according to the method described in patent CN105777553A is added into a batching tank, the batching tank is vacuumized, and then nitrogen is introduced for three times for replacement, so that oxygen isolation is ensured. And transferring the anaerobic water obtained by the preparation into a preparation tank, preparing an aqueous solution of the pentanediamine-adipate with the mass concentration of 70%, and preserving nitrogen for later use.

To the esterification reactor, 4.86g of trimethyl phosphate as a stabilizer was added, and the aqueous solution of pentamethylenediamine-adipic acid salt prepared by the above deoxidized pure water was further added, followed by stirring at about 260℃for about 10 minutes. And transferring the materials in the esterification reaction kettle to a polycondensation reaction kettle under the protection of nitrogen, heating to 280 ℃, vacuumizing to 1kPa, reacting for about 1 hour, switching a high vacuum pump, vacuumizing to below 30Pa, and continuously reacting for 2 hours at the temperature. When the stirring current reaches 0.62A, 0.3MPa nitrogen is filled into the polymerization reaction kettle, and the mixture is subjected to wiredrawing and granulating.

Example 3

Adopting the ultrasonic vacuum deoxidizing device disclosed in CN200520133520.6 to ultrasonically deoxidize pure water, pumping water outwards by using a water pump to form vacuum of-0.03 MPa (gauge pressure) in the sealing tank, injecting water into the sealing tank, compressing the residual gas by using water level rise, increasing the pressure of the gas, automatically opening a check valve with a gas-water separation function at the top of the sealing tank to exhaust outside the sealing tank when the pressure of the gas in the sealing tank is compressed to be greater than the atmospheric pressure, automatically closing the check valve when the internal and external air pressures of the sealing tank are balanced, and controlling the water pump to be 50m ³ At a rate of/h, pumping water to the outside of the tank continuously, and periodically filling water into the sealed tank to form the compression-exhaust process. In the compression-exhaust process, ultrasonic waves are emitted into the sealed tank by an ultrasonic transducer with ultrasonic power of 1MHz, so that water in the sealed tank is subjected to ultrasonic continuous vibration for 45min, and the water is deoxidized. The measurement was carried out using the measurement method described in example 1, and the result showed that the oxygen content in the deoxygenated water was measured to be 0.03mg/L.

To the esterification reactor, 4.86g of trimethyl phosphate as a stabilizer was added, and the aqueous solution of pentamethylenediamine-adipic acid salt prepared by the above deoxidized pure water was further added, followed by stirring at about 260℃for about 10 minutes. And transferring the materials in the esterification reaction kettle to a polycondensation reaction kettle under the protection of nitrogen, heating to 280 ℃, vacuumizing to 1kPa, reacting for about 1 hour, switching a high vacuum pump, vacuumizing to below 30Pa, and continuously reacting for 1 hour and 50 minutes at the temperature. When the stirring current reaches 0.60A, 0.3MPa nitrogen is filled into the polymerization reaction kettle, and the mixture is subjected to wire drawing and granulating.

Example 4

An atmospheric thermal deaerator (purchased from the company of guang gang electric power equipment, atmospheric vacuum deaerator) to deaerate pure water. The working steam pressure of the device is 0.02MPa, the internal pressure of the deaerator is 0.2MPa, the water temperature is 104 ℃, and the contact time of steam and water is 30min. The measurement was carried out using the measurement method described in example 1, and the result showed that the oxygen content of the deoxidized water deoxidized thermally was 0.01mg/L.

To the esterification reactor, 4.86g of trimethyl phosphate as a stabilizer was added, and the aqueous solution of pentamethylenediamine-adipic acid salt prepared by the above deoxidized pure water was further added, followed by stirring at about 260℃for about 10 minutes. And transferring the materials in the esterification reaction kettle to a polycondensation reaction kettle under the protection of nitrogen, heating to 280 ℃, vacuumizing to 1kPa, reacting for about 1 hour, switching a high vacuum pump, vacuumizing to below 30Pa, and continuously reacting for 1 hour and 50 minutes at the temperature. When the stirring current reaches 0.59A, 0.3MPa nitrogen is filled into the polymerization reaction kettle, and the mixture is subjected to wiredrawing and granulating.

Example 5

An oxygen-free aqueous solution of ethylenediamine-adipic acid salt at a concentration of 70% was prepared in the same manner as in example 4, wherein the mass of the ethylenediamine-adipic acid salt was 480g.

Under the protection of nitrogen, 16.0kg of terephthalic acid and 7.48kg of ethylene glycol are added into a 100L esterification reaction kettle, 7.8g of ethylene glycol antimony catalyst and 39.0g of antioxidant 1010 (2000 ppm) are added, the temperature is raised to about 260 ℃ for reaction, low-boiling components are fractionated, and when the reaction is carried out for about 300 minutes, the low-boiling fraction reaches 98% of theoretical amount, and the esterification reaction is finished.

To the esterification reactor, 4.86g of trimethyl phosphate as a stabilizer was added, and then an oxygen-free aqueous solution of 70% concentration of pentamethylenediamine-adipic acid salt prepared by the above-mentioned deoxidized pure water was added, followed by stirring at about 260℃for about 10 minutes. And transferring the materials in the esterification reaction kettle to a polycondensation reaction kettle under the protection of nitrogen, heating to 280 ℃, vacuumizing to 1kPa, reacting for about 1 hour, switching a high vacuum pump, vacuumizing to below 30Pa, and continuously reacting at the temperature for 2 hours and 10 minutes. When the stirring current reaches 0.62A, 0.3MPa nitrogen is filled into the polymerization reaction kettle, and the mixture is subjected to wiredrawing and granulating.

Example 6

Under the protection of nitrogen, 16.0kg of terephthalic acid and 7.48kg of ethylene glycol are added into a 100L esterification reaction kettle, 7.8g of ethylene glycol antimony catalyst and 39.0g of antioxidant 1076 (2000 ppm) are added, the temperature is raised to about 260 ℃ for reaction, low-boiling components are fractionated, and when the reaction is carried out for about 300 minutes, the low-boiling components reach 98% of theoretical quantity, and the esterification reaction is finished.

To the esterification reactor, 4.86g of trimethyl phosphate as a stabilizer was added, and then an oxygen-free aqueous solution of 70% concentration of pentamethylenediamine-adipic acid salt prepared by the above-mentioned deoxidized pure water was added, followed by stirring at about 260℃for about 10 minutes. And transferring the materials in the esterification reaction kettle to a polycondensation reaction kettle under the protection of nitrogen, heating to 280 ℃, vacuumizing to 1kPa, reacting for about 1 hour, switching a high vacuum pump, vacuumizing to below 30Pa, and continuously reacting for 1 hour and 50 minutes at the temperature. When the stirring current reaches 0.59A, 0.3MPa nitrogen is filled into the polymerization reaction kettle, and the mixture is subjected to wiredrawing and granulating.

Example 7

Under the protection of nitrogen, 16.0kg of terephthalic acid and 7.48kg of ethylene glycol are added into a 100L esterification reaction kettle, 7.8g of ethylene glycol antimony catalyst, 19.5g of antioxidant 168 (2000 ppm) and 19.5g of antioxidant 1010 (1000 ppm) are added, the temperature is raised to about 260 ℃ for reaction, low-boiling components are fractionated, and when the reaction is carried out for about 300 minutes, the low-boiling fractions reach 98% of theoretical amount, and the esterification reaction is finished.

To the esterification reactor, 4.86g of trimethyl phosphate as a stabilizer was added, and the above-prepared 70% strength oxygen-free aqueous solution of pentamethylenediamine-adipic acid salt was further added, followed by stirring at about 260℃for about 10 minutes. And transferring the materials in the esterification reaction kettle to a polycondensation reaction kettle under the protection of nitrogen, heating to 280 ℃, vacuumizing to 1kPa, reacting for about 1 hour, switching a high vacuum pump, vacuumizing to below 30Pa, and continuously reacting at the temperature for 1 hour and 55 minutes. When the stirring current reaches 0.61A, 0.3MPa nitrogen is filled into the polymerization reaction kettle, and the mixture is subjected to wiredrawing and granulating.

Example 8

Under the protection of nitrogen, 16.0kg of terephthalic acid and 7.48kg of ethylene glycol are added into a 100L esterification reaction kettle, 7.8g of ethylene glycol antimony catalyst, 9.75g of antioxidant THP-24 (2000 ppm) and 27.75g of antioxidant 1010 (1500 ppm) are added, the temperature is raised to about 260 ℃ for reaction, low-boiling components are fractionated, and when the reaction is carried out for about 300 minutes, the low-boiling components reach 98% of theoretical amount, and the esterification reaction is finished.

To the esterification reactor, 4.86g of trimethyl phosphate as a stabilizer was added, and the above-prepared 70% strength oxygen-free aqueous solution of pentamethylenediamine-adipic acid salt was further added, followed by stirring at about 260℃for about 10 minutes. And transferring the materials in the esterification reaction kettle to a polycondensation reaction kettle under the protection of nitrogen, heating to 280 ℃, vacuumizing to 1kPa, reacting for about 1 hour, switching a high vacuum pump, vacuumizing to below 30Pa, and continuously reacting for 1 hour and 50 minutes at the temperature. When the stirring current reaches 0.63A, 0.3MPa nitrogen is filled into the polymerization reaction kettle, and the mixture is subjected to wiredrawing and granulating.

Example 9

Under the protection of nitrogen, 16.0kg of terephthalic acid and 7.48kg of ethylene glycol are added into a 100L esterification reaction kettle, 7.8g of ethylene glycol antimony catalyst and 19.5g of antioxidant 1010 (1000 ppm) are added, the temperature is raised to about 260 ℃ for reaction, low-boiling components are fractionated, and when the reaction is carried out for about 300 minutes, the low-boiling fraction reaches 98% of theoretical amount, and the esterification reaction is finished.

To the esterification reactor, 4.86g of trimethyl phosphate as a stabilizer was added, and the above-prepared 70% strength oxygen-free aqueous solution of pentamethylenediamine-adipic acid salt was further added, followed by stirring at about 260℃for about 10 minutes. And transferring the materials in the esterification reaction kettle to a polycondensation reaction kettle under the protection of nitrogen, heating to 280 ℃, vacuumizing to 1kPa, reacting for about 1 hour, switching a high vacuum pump, vacuumizing to below 30Pa, and continuously reacting at the temperature for 2 hours and 5 minutes. When the stirring current reaches 0.60A, 0.3MPa nitrogen is filled into the polymerization reaction kettle, and the mixture is subjected to wire drawing and granulating.

Example 10

Under the protection of nitrogen, 16.0kg of terephthalic acid and 7.48kg of ethylene glycol are added into a 100L esterification reaction kettle, 7.8g of ethylene glycol antimony catalyst and 9.75g of antioxidant 1010 (500 ppm) are added, the temperature is raised to about 260 ℃ for reaction, low-boiling components are fractionated, and when the reaction is carried out for about 300 minutes, the low-boiling fraction reaches 98% of theoretical amount, and the esterification reaction is finished.

To the esterification reactor, 4.86g of trimethyl phosphate as a stabilizer was added, and the above-prepared 70% strength oxygen-free aqueous solution of pentamethylenediamine-adipic acid salt was further added, followed by stirring at about 260℃for about 10 minutes. And transferring the materials in the esterification reaction kettle to a polycondensation reaction kettle under the protection of nitrogen, heating to 280 ℃, vacuumizing to 1kPa, reacting for about 1 hour, switching a high vacuum pump, vacuumizing to below 30Pa, and continuously reacting for 1 hour and 45 minutes at the temperature. When the stirring current reaches 0.60A, 0.3MPa nitrogen is filled into the polymerization reaction kettle, and the mixture is subjected to wire drawing and granulating.

Example 11

An oxygen-free aqueous solution of ethylenediamine-adipic acid salt at a concentration of 70% was prepared in the same manner as in example 4, wherein the mass of the ethylenediamine-adipic acid salt was 3200g.

Under the protection of nitrogen, 16.0kg of terephthalic acid and 8.0kg of ethylene glycol are added into a 100L esterification reaction kettle, 7.8g of ethylene glycol antimony catalyst and 9.75g of antioxidant 1010 (500 ppm) are added, the temperature is raised to about 260 ℃ for reaction, low-boiling components are fractionated, and when the reaction is carried out for about 300 minutes, the low-boiling fraction reaches 98% of theoretical amount, and the esterification reaction is finished.

Comparative example 1

Under the protection of nitrogen, 16.0kg of terephthalic acid and 7.48kg of ethylene glycol are added into a 100L esterification reaction kettle, 7.8g of ethylene glycol antimony catalyst is added, the temperature is raised to about 260 ℃ for reaction, low-boiling components are fractionated, and when the reaction is carried out for 300 minutes, the low-boiling components reach 98% of theoretical amount, and the esterification reaction is finished.

To the esterification reactor, 4.86g of trimethyl phosphate as a stabilizer was added, and a non-oxygen-removed pure water solution (the mass concentration was 70% and the mass of the pentylene diamine-adipate was 480 g) of pentylene diamine-adipic acid prepared in advance with non-oxygen-removed pure water was further added, and stirring was continued at 260℃for about 10 minutes. And transferring the materials in the esterification reaction kettle to a polycondensation reaction kettle under the protection of nitrogen, heating to 280 ℃, vacuumizing to 1kPa, reacting for 1 hour, switching a high vacuum pump, vacuumizing to below 30Pa, and continuously reacting for 1 hour and 50 minutes at the temperature. When the stirring current reaches 0.59A, 0.3MPa nitrogen is filled into the polymerization kettle, and the fiber is drawn and granulated.

Comparative example 2

Under the protection of nitrogen, 16.0kg of terephthalic acid and 7.48kg of ethylene glycol are added into a 100L esterification reaction kettle, 7.8g of ethylene glycol antimony catalyst and 39.0g of antioxidant 1010 (2000 ppm) are added, the temperature is raised to about 260 ℃ for reaction, low-boiling components are fractionated, when the reaction is carried out for 300 minutes, the low-boiling fraction reaches 98% of theoretical amount, the esterification reaction is ended, 4.86g of stabilizer trimethyl phosphate is added into the esterification reaction kettle, and a pre-prepared non-oxygen-removed pure water solution of pentanediamine-adipic acid (the mass concentration is 70%, wherein the mass of the pentanediamine-adipic acid salt is 480 g) is added, and stirring is continued for about 10 minutes at 260 ℃. And transferring the materials in the esterification reaction kettle to a polycondensation reaction kettle under the protection of nitrogen, heating to 280 ℃, vacuumizing to 1kPa, reacting for 1 hour, switching a high vacuum pump, vacuumizing to below 30Pa, and continuously reacting for 1 hour and 55 minutes at the temperature. When the stirring current reaches 0.61A, 0.3MPa nitrogen is filled into the polymerization kettle, and the mixture is subjected to wire drawing and granulating.

Comparative example 3

Under the protection of nitrogen, 16.0kg of terephthalic acid and 7.48kg of ethylene glycol are added into a 100L esterification reaction kettle, 7.8g of ethylene glycol antimony catalyst and 39.0g of antioxidant 1076 (2000 ppm) are added, the temperature is raised to about 260 ℃ for reaction, low-boiling components are fractionated, when the reaction is carried out for 300 minutes, the low-boiling fraction reaches 98% of theoretical amount, the esterification reaction is finished, 4.86g of stabilizer trimethyl phosphate is added into the esterification reaction kettle, and a pre-prepared pure water solution without oxygen removal of pentanediamine-adipic acid (the mass concentration is 70%, wherein the mass of the pentanediamine-adipic acid salt is 480 g) is added, and stirring is continued for about 10 minutes at 260 ℃. And transferring the materials in the esterification reaction kettle to a polycondensation reaction kettle under the protection of nitrogen, heating to 280 ℃, vacuumizing to 1kPa, reacting for 1 hour, switching a high vacuum pump, vacuumizing to below 30Pa, and continuously reacting for 2 hours at the temperature. When the stirring current reaches 0.60A, 0.3MPa nitrogen is filled into the polymerization kettle, and the mixture is subjected to wire drawing and granulating.

Comparative example 4

Under the protection of nitrogen, 16.0kg of terephthalic acid and 7.48kg of ethylene glycol are added into a 100L esterification reaction kettle, 7.8g of ethylene glycol antimony catalyst and 39.0g of antioxidant 168 (2000 ppm) are added, the temperature is raised to about 260 ℃ for reaction, low-boiling components are fractionated, when the reaction is carried out for 300 minutes, the low-boiling fraction reaches 98% of theoretical amount, the esterification reaction is finished, 4.86g of stabilizer trimethyl phosphate is added into the esterification reaction kettle, and then deoxidized pure water solution of pentanediamine-adipic acid prepared in advance is added, and stirring is continued for about 10 minutes at 260 ℃. And transferring the materials in the esterification reaction kettle to a polycondensation reaction kettle under the protection of nitrogen, heating to 280 ℃, vacuumizing to 1kPa, reacting for 1 hour, switching a high vacuum pump, vacuumizing to below 30Pa, and continuously reacting for 1 hour and 50 minutes at the temperature. When the stirring current reaches 0.59A, 0.3MPa nitrogen is filled into the polymerization kettle, and the fiber is drawn and granulated.

Comparative example 5

Under the protection of nitrogen, adding 16.0kg of terephthalic acid and 7.48kg of ethylene glycol into a 100L esterification reaction kettle, adding 7.8g of ethylene glycol antimony catalyst and 39.0 of antioxidant THP-24 (2000 ppm), heating to about 260 ℃ for reaction, fractionating out low-boiling components, when the reaction is carried out for 300 minutes, the low-boiling fraction reaches 98% of theoretical amount, ending the esterification reaction, adding 4.86g of stabilizer trimethyl phosphate into the esterification reaction kettle, adding deoxidized pure water solution of pentanediamine-adipic acid prepared in advance, and continuously stirring for about 10 minutes at 260 ℃. And transferring the materials in the esterification reaction kettle to a polycondensation reaction kettle under the protection of nitrogen, heating to 280 ℃, vacuumizing to 1kPa, reacting for 1 hour, switching a high vacuum pump, vacuumizing to below 30Pa, and continuously reacting for 2 hours and 10 minutes at the temperature. When the stirring current reaches 0.61A, 0.3MPa nitrogen is filled into the polymerization kettle, and the mixture is subjected to wire drawing and granulating.

Comparative example 6

Under the protection of nitrogen, 16.0kg of terephthalic acid and 7.48kg of ethylene glycol are added into a 100L esterification reaction kettle, 7.8g of ethylene glycol antimony catalyst and 19.5g of antioxidant 1010 (1000 ppm) are added, the temperature is raised to about 260 ℃ for reaction, low-boiling components are fractionated, when the reaction is carried out for 300 minutes, the low-boiling fraction reaches 98% of theoretical amount, the esterification reaction is ended, 4.86g of stabilizer trimethyl phosphate is added into the esterification reaction kettle, and a pre-prepared non-oxygen-removed pure water solution of pentanediamine-adipic acid (the mass concentration is 70%, wherein the mass of the pentanediamine-adipic acid salt is 480 g) is added, and stirring is continued for about 10 minutes at 260 ℃. And transferring the materials in the esterification reaction kettle to a polycondensation reaction kettle under the protection of nitrogen, heating to 280 ℃, vacuumizing to 1kPa, reacting for 1 hour, switching a high vacuum pump, vacuumizing to below 30Pa, and continuously reacting for 2 hours at the temperature. When the stirring current reaches 0.60A, 0.3MPa nitrogen is filled into the polymerization kettle, and the mixture is subjected to wire drawing and granulating.

Comparative example 7

Under the protection of nitrogen, 16.0kg of terephthalic acid and 7.48kg of ethylene glycol are added into a 100L esterification reaction kettle, 7.8g of ethylene glycol antimony catalyst and 9.75g of antioxidant 1010 (500 ppm) are added, the temperature is raised to about 260 ℃ for reaction, low-boiling components are fractionated, when the reaction is carried out for 300 minutes, the low-boiling fraction reaches 98% of theoretical amount, the esterification reaction is ended, 4.86g of stabilizer trimethyl phosphate is added into the esterification reaction kettle, and a pre-prepared non-oxygen-removed pure water solution of pentanediamine-adipic acid (the mass concentration is 70%, wherein the mass of the pentanediamine-adipic acid salt is 480 g) is added, and stirring is continued for about 10 minutes at 260 ℃. And transferring the materials in the esterification reaction kettle to a polycondensation reaction kettle under the protection of nitrogen, heating to 280 ℃, vacuumizing to 1kPa, reacting for 1 hour, switching a high vacuum pump, vacuumizing to below 30Pa, and continuously reacting for 1 hour and 55 minutes at the temperature. When the stirring current reaches 0.61A, 0.3MPa nitrogen is filled into the polymerization kettle, and the mixture is subjected to wire drawing and granulating.

The polyester amide resins prepared in the above examples and comparative examples were subjected to performance test in which the intrinsic viscosity [. Eta.](dL/g) reference ASTM D4603-2003, melting Point T _m Referring to GB/T19466.3-2004, the yellowness index referring to ASTM D6290-2013, test results are shown in Table 1 below.

TABLE 1

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

1. in the above table data, the results of the tests of comparative examples 1 to 4 and comparative example 1 revealed that the polyester amide product obtained in the examples in which the pentylene diamine-adipate was dissolved by using the oxygen-scavenging pure water obtained in the different methods was significantly improved in yellow index relative to the product obtained in comparative example 1 by using the ordinary pure water.

The reason for the speculation may be: at normal temperature, the normal pure water contains about 50ppm of dissolved oxygen. Although the dissolved oxygen is not large, these oxygen molecules are involved in the reaction side reactions during the polyester amide reaction. Because of the existence of active groups such as amino groups, amide bonds and the like in the reaction raw materials, and simultaneously because dihydric alcohol serving as a raw material can generate a certain amount of aldehyde byproducts in the esterification process, the two groups are extremely easy to generate side reactions at high temperature to generate byproducts such as imines. After entering the polycondensation reaction kettle, if oxygen exists, the byproducts further undergo oxidation, chain scission or side reactions participated by oxygen free radicals, so as to produce byproducts containing the conjugated structure chromophore. Therefore, the oxygen removal of the aqueous solution at the initial stage of the reaction greatly reduces the side reaction of the participation of oxygen, and further reduces the thermal oxygen decomposition of the polyesteramide in the reaction process.

2. As is clear from comparative examples 4 to 7, the yellow index of the obtained polyesteramide was further lowered by adding an appropriate amount of an antioxidant. From this, it can be seen that the hindered classification antioxidant has a better effect than the phosphorous acid antioxidant. Among them, antioxidant 1010 works best.

While it can be seen from comparative examples 5 to 7 that the effect of using different antioxidant combinations on the reduction of the yellow index of the product is also different. The effect is optimal when 2000ppm of antioxidant 1010 is used. When 500ppm of antioxidant 168 is compounded with 1500ppm of antioxidant 1010 and 1000ppm of antioxidant THP-24 is compounded with 1000ppm of antioxidant 1010, the yellow index of the product is reduced to a certain extent. The corresponding comparative examples 2, 3 also show that the antioxidant can improve the color of the product even in pure water without oxygen. But the antioxidant effect is more obvious under the condition of deoxidizing, and the yellow index of the product is greatly reduced.

3. When example 6 is compared with comparative examples 3 to 5, it is found that the yellow index of the product is somewhat lowered by adding the antioxidant, but the excellent effect as in example can be obtained only by simultaneously deoxidizing the solution.

4. Comparative example 10 and example 11, after increasing the addition amount of nylon salt and the content of ethylene glycol added, a stable polyesteramide product was still obtained. However, the product of example 11 has a significantly increased yellowness index and a reduced melting point compared to example 10, mainly because the added polyamide structure further destroys the stability of the polyester structure.

5. As can be seen from comparative examples 4, 9, 10 and comparative examples 2, 6, 7, the addition of different amounts of antioxidant also has different effects on the color improvement of the product. Relatively, the use amount of the antioxidant with larger use amount can further reduce the yellow index of the product, the use amount of the antioxidant is increased from 500ppm to 2000ppm, the yellow index of the product can be further reduced, but when the use amount is 1000ppm, the effect of reducing the yellow index is most obvious, and after the use amount of the antioxidant is further increased, the effect of improving the yellow index is reduced. Considering that the production cost can be correspondingly increased by increasing the dosage of the antioxidant, the dosage of the antioxidant 1010 is 1000 ppm.

The wet chips of the polyesteramides prepared in examples and comparative examples were respectively tested in the following manner to prepare polyesteramide FDY fibers of test examples 1 to 11 and comparative examples 1s to 7 s.

After pre-crystallization for 2 hours at 140 ℃, the obtained product is heated to 150 ℃ and dried for 20 hours, thus obtaining a dried slice.

The dried slices were spun at 255 ℃, with a first hot plate temperature of 80 ℃, speed of 1500m/min, and then into a second hot plate, with a hot plate temperature of 160 ℃, speed of 3750m/min. Drawing the fiber between the first hot plate and the second hot plate, wherein the drawing multiple is 2.5 times; and (3) feeding the fiber bundles from the second guide disc into a winding machine for winding, wherein the winding speed is 3700m/min, and the polyester amide FDY fibers are obtained after winding.

The above-mentioned polyester amide FDY fiber was subjected to the relevant mechanical properties test, wherein the breaking strength (CN/dtex) and the elongation at break (%) were both as described in GB/T3916-1997 "determination of textile force at break and elongation at break for individual yarns of textile package yarn", and the relevant test results are shown in Table 2.

The fiber is dyed in red acid dye with the bath ratio of 1:20 for 60 minutes at the normal pressure of 100 ℃, dried after washing, and the product dye-uptake (%) is detected, and specific reference can be made to FZ/T54037-2011, namely cationic dye dyeable polyester drawn yarn, and the relevant test results are shown in Table 2.

TABLE 2

From the test results of table 2 above, it can be seen that:

1. the comparative test examples 1 to 4 and comparative examples 1s to 3s show that the breaking strength of the products after deoxidizing the salt solution by using different modes is greatly improved, the modulus is high, and the dyeing rate is also obviously improved. It is shown that the oxygen removal from the salt solution is more beneficial for the embedding of the polyamide structure into the main structure of the polyester, and reduces the degradation of the product due to the formation of by-products. Meanwhile, the reduction of the content of byproducts reduces the generation of small molecules, and further helps to improve the fiber performance in the spinning process. On the premise of ensuring the deoxidizing effect of the anaerobic water, each deoxidizing mode has little influence on the reaction, has good effect, and can select different deoxidizing methods according to experiment or production requirements.

2. As can be seen from comparative examples 5 to 8, different antioxidants also have a certain influence on the properties of the fibre product. In general, the addition of the antioxidant slightly reduces the strength of the fiber, and particularly, the compound antioxidant has a large influence on the strength of the product, and the strength of the product can be maintained to a certain extent by independently adding the antioxidant 1010.

In contrast, the comparative test examples 5 and 6 and comparative examples 2s and 3s show that the deoxidization of the solvent water still has a great influence on the product performance after the antioxidant is added, and the product performance after deoxidization is obviously improved. While the comparison of comparative examples 2s to 4s shows that even after oxygen removal, the effect of using the antioxidant 168 and the antioxidant THP-24 alone is significantly inferior to that of the antioxidant 1010 without oxygen removal. Therefore, the antioxidant has a great influence on the performance of the deoxidized product.

3. Comparative examples 5, 9, 10 and comparative examples 2s, 6s, 7s show that the amount of antioxidant added is inversely related to the strength of the final fiber. The more antioxidant is added, the fiber strength of the product will decrease to some extent, wherein in test example 9, the decrease in fiber strength is less and the strength is maintained. After the antioxidant is added, the initial modulus of the product can be reduced to a certain extent, the rigidity of the product is reduced, and the softness is better.

4. Comparing test example 10 with test example 11, after increasing the addition amount of nylon salt and the content of ethylene glycol, the obtained polyamide product was decreased in strength and modulus, but the dyeing property was remarkably improved. Mainly because of the introduction of amide bond, the regularity of the polyester structure is destroyed, the crystallization performance of the product is reduced, more amorphous areas are generated, and the wrapping and attaching of the coloring agent are facilitated. Meanwhile, the introduction of the amide bond is more beneficial to the connection of the acid dye and the polymer main body structure, and the dyeing performance is further improved.

In summary, the polyester amide production process provided by the invention has the advantages of simple process and high production efficiency, and can be put into use by simple modification on the basis of the existing polyester production device. The method can further and very effectively reduce the problem of deeper yellow index of the polyester amide product in the polymerization process, reduce the increase of byproducts of the product caused by thermal degradation and thermal oxygen degradation, and ensure that the product fiber has simple preparation process and can be spun smoothly in a common polyester spinning device. The new technology improves the yellowing problem of the product and further improves the fiber performance. When the addition amount of the antioxidant is controlled, satisfactory fiber performance can be obtained, the subsequent manufacturing requirements are met, and the method is suitable for industrial production.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.

Claims

1. A process for the preparation of a polyesteramide, the process comprising the steps of:

3) After the reaction of the step 2), transferring the product obtained in the step 2) into a polycondensation reaction kettle for polycondensation, and ending the polycondensation reaction when the intrinsic viscosity of the polycondensation product reaches 0.3-1.8 dL/g to obtain polyesteramide;

An antioxidant is also added in the step 1), and at least comprises a hindered phenol antioxidant;

the oxygen-removed water has a dissolved oxygen content of less than 0.2mg/L at 25 ℃ and 1 standard atmospheric pressure;

the terephthalic acid and/or the derivative thereof is selected from one or more of terephthalic acid or a compound in which hydrogen on a benzene ring of terephthalic acid is wholly or partially substituted by alkane with 1-4 carbon atoms.

2. The method according to claim 1, wherein in step 1),

the dihydric alcohol is selected from aliphatic dihydric alcohols with carbon chain length of 2-18; and/or the number of the groups of groups,

the hindered phenol antioxidant comprises antioxidant 1010, antioxidant 1076, antioxidant 1098, antioxidant 3114, antioxidant 245 and antioxidant GA-80.

3. The method of claim 1, further comprising the step of adding an additive to the esterification reactor, wherein the additive is selected from the group consisting of a heat stabilizer selected from one or more of phosphoric acid, phosphorous acid, hypophosphorous acid compounds, phosphate esters compounds, phosphites compounds, and phosphines compounds; and/or the number of the groups of groups,

the molar ratio between the dihydric alcohol and the terephthalic acid and/or the derivative thereof is (1.1-2.6): 1.

4. A process according to claim 3, wherein in step 1) the molar ratio between the diol and terephthalic acid and/or its derivatives is from (1.2 to 2.0): 1.

5. The process according to claim 3, wherein the mass ratio between the phosphorus atom in the heat stabilizer and the theoretical yield of the polyesteramide is 1 to 200ppm.

6. The process according to claim 3, wherein the mass ratio between the phosphorus atoms in the heat stabilizer and the theoretical yield of the polyesteramide is from 5 to 150ppm.

7. The process according to claim 3, wherein the mass ratio between the phosphorus atoms in the heat stabilizer and the theoretical yield of the polyesteramide is from 10 to 100ppm.

8. The method according to claim 1, wherein in step 2),

in the deoxidized water, the content of dissolved oxygen is less than 0.1mg/L at 25 ℃ and 1 standard atmospheric pressure; and/or the number of the groups of groups,

the nylon salt is formed by dibasic acid and diamine, wherein the diamine is aliphatic diamine with the carbon chain length of 2-18;

the dibasic acid is selected from aliphatic dibasic acid with carbon chain length of 4-20.

9. The method of claim 8, wherein in step 2) the oxygen-scavenging water has a dissolved oxygen content of less than 0.05mg/L at 25 ℃ and 1 normal atmospheric pressure.

10. The method according to claim 1, wherein the mass ratio between the antioxidant addition amount and the total mass of the polyesteramide is 3000ppm or less; and/or the number of the groups of groups,

the molar ratio between the nylon salt and the terephthalic acid and/or the derivative thereof is (0.005-3): 1.

11. The method according to claim 1, wherein the mass ratio between the antioxidant addition amount and the total mass of the polyesteramide is 20 to 3000ppm; and/or the number of the groups of groups,

the molar ratio between the nylon salt and terephthalic acid and/or its derivative is (0.01-0.3): 1.

12. The method according to claim 1, wherein the molar ratio between the nylon salt and terephthalic acid and/or its derivatives is (0.015-0.25): 1.

13. The method of claim 1, wherein,

the mole ratio of the nylon salt, the dihydric alcohol, the terephthalic acid and/or the derivative thereof is (0.002-99): 1-3): 1.

14. The method of claim 1, wherein,

in the step 3), after the reaction in the step 2), the reaction product is transferred into a polycondensation reaction kettle for polycondensation under the protection of nitrogen or inert gas, and the intrinsic viscosity of the polycondensation product to be measured reaches 0.3-1.8 dL/g, so that the polycondensation reaction can be finished.

15. A polyesteramide prepared by the preparation process according to any of claims 1 to 14.

16. A fiber prepared from the polyesteramide of claim 15.