Patent Description:
Due to its excellent mechanical properties and textile processing performance, the output of nylon fiber ranked No.<NUM> in synthetic fibers area since nylon fiber is invented. As the development of polyester and the disadvantage of high cost, the output of nylon fiber stranded at second place in synthetic fibers area. In <NUM>, China's nylon output is <NUM> million tons, increasing <NUM>% compared to the same period of last year, and its output accounted for <NUM>% of the total output of synthetic fibers. Nylon fiber has excellent physical performance compared to that of polyester fiber, such as high breaking strength, top wear resistance, good moisture absorption, elastic recovery and fatigue resistance, good dyeing performance. Nylon fiber has wide application in other industries besides garment industry and decoration, such as tire cord fabric, automotive textiles, filter materials and BCF carpet bulked yarn. There are many varieties of nylon fiber, the main varieties are nylon <NUM> and nylon <NUM> fiber, due to historical reasons and the specific conditions of different countries, each country's emphasis is also different. The United States, Britain and other countries focus producing nylon <NUM>, and Germany, Italy, Japan and East European countries mainly produce nylon <NUM>, China's main product in this field is also nylon <NUM> fiber.

Continuous hydrolysis polymerization of caprolactam is the most widely applied producing method of the polymerization of nylon <NUM>. In nylon <NUM> chip production, when the polymer reaches equilibrium, the conversion of caprolactam is generally around <NUM>%, which means that about <NUM>% of the caprolactam and oligomer remained in the polymer (monomer accounted for about <NUM>%, low polymer, mainly cyclic dimers, for about <NUM>%), are commonly removed by hot water in the production process and are therefore also referred to as hot water extractable contents. During the melt spinning of nylon <NUM>, impurities of no larger than <NUM> are allowed in the melt, and caprolactam monomer should be as few as possible, because in the high-speed spinning process, the fiber tension is large, the presence of impurities or bubbles will cause stress concentration, resulting in wire breaking phenomenon. The melting temperature of cyclic dimer is <NUM>, far higher than that of nylon <NUM> conventional spinning temperature. Therefore, it cannot melt and cannot participate in ring opening polymerization in molten state. Caprolactam can easily volatilize at the spinning temperature, and bubbles can be easily formed during the fiber forming process; therefore, caprolactam has become an important role affecting the spinning process. The presence of other oligomers in the melt also causes the relative molecular weight distribution to broaden. The presence of low molecular weight polymers not only affects the spinning process, but also affects the mechanical properties of the fibers. Therefore, in the spinning process of nylon <NUM>, in order to avoid broken wire in the spinning process, hot water extractable content should be less than <NUM>%.

Therefore, it is necessary to extract polyamide <NUM> chips before spinning. According to FZ/T <NUM>-<NUM>, polycaprolactam chip hot water extractables content should be less than <NUM>% (good grade), but this process needs to consume a large amount of energy and water for extraction, and it is also a waste of raw materials. Therefore, how to reduce the oligomers produced during the polymerization of caprolactam and further realize the melt spinning of polyamide <NUM> has become one of the restrictive factors for the development of polyamide <NUM> fiber production. Therefore, developing new polymerization process to reduce the oligomer content of caprolactam hydrolysis polymerization and realization of nylon <NUM> melt spinning has become a trend of industrial development.

At present, the main method to reduce the content of oligomers during the hydrolysis polymerization of caprolactam is to control the polymerization temperature, because caprolactam polymerization is a balanced relationship that varies with temperature. With the increase of temperature, it is more conducive to oligomers formation, especially the formation of cyclic oligomers. Therefore, contents of oligomers can be effectively controlled by controlling polymerization temperature, which is low temperature polymerization. In order to ensure that the polymerization is carried out in the liquid state, the polymerization temperature must be at least than <NUM> lower than the melting point of the polyamide <NUM>. In this case, polymerization temperature still cannot control oligomers in the range of melt direct spinning, and low temperature polymerization has another drawback, that is, slower reaction speed and lower molecular weight of polymers obtained. The process of polymerization at lower temperature is divided into two parts, one part is the melting polymerization process, a part is the process of solid phase polymerization, the solid-phase polymerization process is to obtain a polymer of sufficient molecular weight for product development, but no effective method has been found to convert a solid polymer formed at low temperatures into a suitable spinning. If the fibers are spun from a low temperature polymer, the polymer must first be melted, however, in this case, the low molecular weight compounds would be formed with the balance related to the time and temperature. The amount corresponds to the temperature at which it is melted and it is always more than that when it is polymerized at a low temperature, so that there is no advantage compared to the normal polymerization.

<CIT> discloses a two step hydrolysis and polycondensation process followed by further polymerisation and spinning.

In the present invention, polyamide <NUM> prepolymer is prepared at a low temperature, the oligomer content in the melt is controlled in advance, and then, using the method of polycondensation reaction kinetics to strengthen the cyclic oligomer before a large number of generations of aggregation have completed, to obtain a certain molecular weight of nylon <NUM> polymer melt. In this method, the reaction time at high temperature can prevent the formation of large amounts of cyclic oligomers over time at higher melt temperatures.

This invention provides a method of polymerization and melt direct spinning of nylon <NUM>.

A polymerization method of nylon <NUM>, using the method of stepwise polymerization, process is as follows:
The first step is ring-opening reaction. Caprolactam, deionized water and catalyst are mixed to prepolymerization at the temperature of <NUM>-<NUM> and pressure of <NUM>-<NUM> MPa. In this part, caprolactam is formed after the formation of aminocaproic acid prepared under the effect of temperature, pressure and ring-opening water. Afterwards, aminocaproic acid reacts with caprolactam and form short polymer chains. The ring opening degree of caprolactam increase with the reaction proceed. The temperature used in this stage is low. The formation of cyclic oligomers is a thermodynamic equilibrium reaction. The low reaction temperature is beneficial to reduce the content of cyclic oligomer. Meanwhile, the polymer chains formed in this section are short, which present rigid. The activation energy of terminal-amino-bite increase when the polymer chains present rigid. Thus, the content of cyclic oligomer decrease.

The number-average molar mass, cyclic oligomer content, melt viscosity of the product of the first step are <NUM>-<NUM>, <NUM>-<NUM> %, <NUM>-<NUM> Pa • s, respectively. The cyclic oligomer content is below <NUM> %.

The second step is pre-polycondensation, at a pressure of <NUM>-<NUM> Pa, a temperature of <NUM>-<NUM>. The main reaction of this step is polycondensation. The purpose of this section is to increase the molecular weight, and abstraction of the monomer and water under low pressure condition. When molecular weight of nylon <NUM> chains increases to about <NUM>, which is entanglement point, the viscosity of polymer melt increases greatly with the molecular weight increase. In order to control the content of oligomer, the reaction temperature must maintain relatively low level. Moreover, in order to remove small molecules, the viscosity of polymer melt must to maintain relatively low level. Thus, the molecular weight of polymer should control around the entanglement point in this section.

The number-average molar mass, cyclic oligomer content, cyclic dimer content, melt viscosity of the product of the second step are <NUM>-<NUM>, <NUM>-<NUM> %, <NUM>%, <NUM>-<NUM> Pa • s, respectively.

The third step is strengthening stage of polymerization kinetics, at a pressure of <NUM>-<NUM> Pa, a temperature of <NUM>-<NUM> increase to <NUM>-<NUM>. The molecular weight, relative viscosity and melt viscosity of the product of the third step are <NUM>-<NUM> and <NUM>-<NUM>, respectively. The cyclic oligomer content and cyclic dimer content are below <NUM>% and <NUM>%. The purpose of this section is to increase molecular weight to desired value. Thus, the reaction temperature need to be raised. In order to avoid the oligomer content increase with reaction time increase, the small molecules should be dislodged from melt and molecular weight increase to desired value quickly. Thus, the melt viscosity of polymer should be relatively low. The polymerization temperature is gradually increased from <NUM>-<NUM> to <NUM>-<NUM>. The step is to increase the temperature of the melt as the molecular weight increases in order to ensure that the melt viscosity is at a low level. Considering the high temperature is conducive to the formation of oligomers, the gradient heating method is adopted to ensure the melt viscosity is <NUM>-<NUM> Pa·s. After the strengthening stage of the polymerization kinetics, the nylon <NUM> polymer is obtained.

As a preferred technical proposal:
A nylon <NUM> polymerization method as mentioned above, the water content is <NUM>-20wt% of caprolactam, and the catalyst content is <NUM>-20wt% of caprolactam.

A polymerization method of nylon <NUM> as mentioned above, the catalyst is amino acid and/or protonic acid, the protonic acid is one or more material as follow, HCl, H<NUM>PO<NUM>, H<NUM>SO<NUM>, HNO<NUM>, NH<NUM>, [Al(H<NUM>O)<NUM>].

A polymerization method of nylon <NUM> as mentioned above, the amino acid is aliphatic amino acid and aromatic amino acid. The structure of aliphatic amino acid is NH<NUM>(CH<NUM>)xCOOH, in which x=<NUM>~<NUM>. The structure of aromatic amino acid exist aromatic ring in backbone and branched chain, such as phenylalanine.

A polymerization method of nylon <NUM> as mentioned above, the time of ring-opening reaction is <NUM>-<NUM>.

A polymerization method of nylon <NUM> as mentioned above, the time of pre-polycondensation is <NUM>-<NUM>.

A polymerization method of nylon <NUM> as mentioned above, the time of strengthening of polycondensation kinetics is <NUM>-<NUM>.

A polymerization method of nylon <NUM> as mentioned above, temperature increase by multistep means the temperature increase process from <NUM>-<NUM> increase to <NUM>-<NUM> is divide into <NUM>-<NUM> sections, to realize the temperature increase with the reaction react.

A polymerization method of nylon <NUM> as mentioned above, using a liquid-phase tackifying polymerizer to realize the strengthening of polycondensation kinetics.

A polymerization method of nylon <NUM> as mentioned above, molecular weight stabilizing agents can be added during the ring-opening, pre-polycondensation, or/and strengthening of polycondensation kinetics. The molecular weight stabilizing agents are one or more material as follow, monoacid, monoamine, polyatomic acid and polyamine. The addition is <NUM>-10wt%, relative to caprolactam.

Monoacid, aliphatic series, H(CH<NUM>)aCOOH, a=<NUM>~<NUM>. Or aromatic series, such as benzoic acid.

Monoamine, aliphatic series, H(CH<NUM>)bNH, b=<NUM>~<NUM>. Or aromatic series, such as phenylamine.

Polyatomic acid, aliphatic diacid, HOOC(CH<NUM>)cCOOH, c=<NUM>-<NUM>. Or aromatic diacid, such as phthalandione, m-phthalic acid, terephthalic acid or naphthalic acid.

Polyamine, aliphatic diamine, H<NUM>N(CH<NUM>)aNH<NUM>, d=<NUM>-<NUM>. Or aromatic diamine, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine or xylylenediamine.

A polymerization method of nylon <NUM> as mentioned above, lactam or/and lactone, corresponding polymer can be added during the ring-opening, pre-polycondensation, or/and strengthening of polycondensation kinetics, the addition is under 50wt%, relative to caprolactam.

A polymerization method of nylon <NUM> as mentioned above, corresponding polymer is the homopolymer or copolymer of lactam or/and lactone. Lactam is
<CHM>
, lactone
<CHM>
n=<NUM>~<NUM>, m=<NUM>~<NUM>. The molecular of homopolymer or copolymer is under <NUM>.

A polymerization method of nylon <NUM> as mentioned above, antioxygen, ultravioresistant agents, antibacterial agents, fire retardants, negative ion generator, fluorescent materials, carbon nanotubes, graphene can be added during the ring-opening, pre-polycondensation, or/and strengthening of polycondensation kinetics, the addition is <NUM>-10wt%, relative to caprolactam.

A polymerization method of nylon <NUM> as mentioned above, antioxygen is antioxygen1010, antioxygen169 or antioxygen616. Ultravioresistant agents are salicylic acid, benzophenone series, benzotriazole series, titanium dioxide, zinc oxide, calcium carbonate, talcum powder, SEED. Antibacterial agents are nano-titanium dioxide, zinc oxide, ferric oxide, chitosan, nano-Ag, nano-Cu, quaternary ammonium salt series. Fire retardants are zinc borate, tetrabromobisphenol A, Bis(hexachlorocyclpentadiene) cyclooctane, ammonium polyphosphate, Decabromodiphenyl ether, complex of <NUM>,<NUM>,<NUM>-(<NUM>,<NUM>,<NUM>-triazine-<NUM>,<NUM>,<NUM>-triyltriimino) tris and melamine. Negative ion generators are tourmaline, opal, qicai stone. Fluorescent materials are alkali metal chalcogenide or/and aluminate as luminous substrate, lanthanides, such as Eu, Sm, Er or/and Nd as ctivating agents.

A polymerization method of nylon <NUM> as mentioned above, the structure of quaternary ammonium salt is
<CHM>
R<NUM>, R<NUM>=C8~C20, R<NUM> and R<NUM> can be the same or different. X-is Cl-, Br-, I-.

A polymerization method of nylon <NUM> as mentioned above, in order to accelerate tackifying, chain extenders can be added during the strengthening of polycondensation kinetics. The addition amount of chain extenders is <NUM>-<NUM> wt%, relative to caprolactam. The chain extenders are dioxins, bis-oxazole ketone, adipoyl biscaprolactamate, phosphate, diisocyanate. The structure of dioxins is
<CHM>
R=C1-C8.

This invention provides a melt directly spinning method. After strengthening of polycondensation kinetics, the nylon <NUM> melt is spun directly. The spinning temperature is <NUM>-<NUM>, the first spinning reel speed is <NUM>-<NUM>/min, the second spinning reel speed is <NUM>-<NUM>/min, draw ratio is <NUM>-<NUM>, wind temperature is <NUM>-<NUM>, wind speeds is <NUM>-<NUM>/s, relative humidity is <NUM>-<NUM>%. Finally, full-drawn yarn is obtained.

A melt directly spinning method of nylon <NUM> as mentioned above. After strengthening of polycondensation kinetics, the nylon <NUM> melt is spun directly. The spinning temperature is <NUM>-<NUM>, the spinning speed is <NUM>-<NUM>/min, wind temperature is <NUM>-<NUM>, wind speeds is <NUM>-<NUM>/s, relative humidity is <NUM>-<NUM>%. Finally, unoriented yarn is obtained.

A melt directly spinning method of nylon <NUM> as mentioned above. After strengthening of polycondensation kinetics, the nylon <NUM> melt is spun directly. The spinning temperature is <NUM>-<NUM>, the spinning speed is <NUM>-<NUM>/min, wind temperature is <NUM>-<NUM>, wind speeds is <NUM>-<NUM>/s, relative humidity is <NUM>-<NUM>%. Finally, pre-oriented yarn is obtained.

A melt-spinning method of nylon <NUM> polymer as mentioned above, the nylon <NUM> polymer spun immediately in accordance with a Nylon <NUM> spinning process, after the polycondensation reaction kinetics strengthening process. The spinning temperature is <NUM>-<NUM>, the cooling air temperature is <NUM>-<NUM> and the wind speed is <NUM>-<NUM>/s, the relative humidity is <NUM>%-<NUM>% to obtain a highly oriented silk.

A melt-spinning method of nylon <NUM> polymer as described above, the nylon <NUM> polymer is immediately spun into bulked silk in accordance the with Nylon <NUM> spinning process, after the polycondensation reaction kinetics strengthening process. the spinning temperature is <NUM>-<NUM>, the cooling air temperature is <NUM>-<NUM> and the wind speed is <NUM>-<NUM>/s, the relative humidity is <NUM>%-<NUM>%, the feeding roll temperature is <NUM>-<NUM>, the stretching roll temperature is <NUM>-<NUM>, the feeding speed is <NUM>-<NUM>/min, the stretching speed of <NUM>-<NUM>/min, the stretching multiples is <NUM>-<NUM> times, the deformation hot air temperature is <NUM>-<NUM>, the air jet pressure is 196kPa-490kPa, the winding speed is <NUM>-<NUM>/min, the cooling air temperature is <NUM>.

A melt-spinning method of nylon <NUM> polymer as described above, The nylon <NUM> polymer is directly applied to composite spinning after the polycondensation kinetic strengthening process is finished, and the composite spinning is a side-by-side type, a sheath-core type, a sea-island type, a petal type or a multi-core type composite spinning; the composite spinning in nylon <NUM> another component is one of 6T, nylon <NUM>, nylon nylon <NUM>, nylon <NUM>, nylon <NUM>, nylon <NUM>, nylon <NUM>, nylon <NUM>, nylon <NUM>, nylon <NUM>, nylon, branched water-soluble poly a vinegar. The mass ratio of the nylon <NUM> polymer to another component is <NUM>: <NUM>-<NUM>: <NUM>.

A melt-spinning method of nylon <NUM> polymer as described above, The shape of the spinneret is triangular, cross, polygon, hollow fiber, U, T, Y, polygon, or zigzag.

A melt-spinning method of nylon <NUM> polymer as described above, the nylon <NUM> polymer enhanced in polycondensation kinetics after the end of the process, in the melt conveying process, add polymer slices, mixing immediately in accordance with the nylon <NUM> spinning process of direct spinning, the polymer slice is added to nylon <NUM> melt <NUM>-30wt%.

A melt-spinning method of nylon <NUM> polymer as described above, the matrix of functional masterbatch or color masterbatch is one or more of nylon, polyester, polyethylene glycol.

A melt-spinning method of nylon <NUM> polymer as described above, Nylon is one or more of nylon <NUM>, nylon 6T, nylon <NUM>, nylon <NUM>, nylon <NUM>, nylon <NUM>, nylon <NUM>, nylon <NUM>, nylon <NUM>, nylon <NUM>, nylon <NUM>; Polyester is one or more of polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, and water-soluble polyester; Polyethylene glycol has a molecular weight in the range of <NUM>-<NUM>, The polyethylene glycol is either the hydroxyl group or the polyethylene glycol, which is modified to be a spindle or amino group.

A melt-spinning method of nylon <NUM> polymer as described above, Described in the functional masterbatch contains functional additives are antioxidants, uv resistant agent, antibacterial agent, flame retardant, anion generation materials, fluorescent material, carbon nanotubes or graphene, and the content is <NUM>-30wt% of functional masterbatch.

A melt-spinning method of nylon <NUM> polymer as described above, The antioxidant is antioxidant <NUM>, antioxidant <NUM> or antioxidant <NUM>; The anti-uv agent is salicylic acid, diphenylketone and triazole, titanium dioxide, zinc oxide, calcium carbonate, talcum powder, SEED; Antibacterial agent is nano titanium dioxide, zinc oxide, iron oxide, chitosan, nano silver, nano copper or quaternary ammonium compounds; The flame retardants are zinc borate, tetraosmol bisphenol A, bis(hexachlorocyclopentadiene)cyclooctane, ammonium polyphosphate, decabromodiphenyl ether or <NUM>,<NUM>,<NUM>-tris(<NUM>,<NUM>-diamino) A <NUM>-thio-triazine) mixture of hexane and cyanuric acid; The anion generating material is bizarre stone, tourmaline, opal, or sculpted stone; Fluorescent materials are based on alkaline earth metal sulfide, aluminate as a luminescent substrate, with rare earth copper-based elements of europium, samarium, erbium or neodymium as an activator.

A method of melt spinning a nylon <NUM> polymer as described above, the molecular formula is
<CHM>
Among them, R<NUM>, R<NUM>=C8~C20, R<NUM>, R<NUM> is the same or different;X-is Cl-, Br-, I-.

A melt-spinning method of nylon <NUM> polymer as described above, the colorants used in the masterbatch are one or more of the phthalocyanine red, phthalocyanine blue, phthalocyanine green, fast red, macromolecular red, macromolecular yellow, permanent yellow, permanent Purple, azo red, cadmium red, cadmium yellow, titanium dioxide, carbon black, iron oxide red, yellow iron oxide, pigment red <NUM>, pigment blue <NUM>, pigment green <NUM>, pigment yellow <NUM>, pigment orange <NUM>, pigment orange <NUM>, pigment brown <NUM>, pigment yellow <NUM>, solvent violet <NUM>, solvent violet <NUM>, solvent red <NUM>, solvent red <NUM>, solvent blue <NUM>, solvent blue <NUM>, solvent green <NUM>, solvent yellow <NUM>, solvent yellow <NUM>.

A melt-spinning method of nylon <NUM> polymer as described above, the nylon <NUM> polymer enhanced in polycondensation kinetics after the end of the process, in the melt conveying process, add polymer slices, mixing immediately in accordance with the nylon <NUM> spinning process of direct spinning, the polymer slice is added to nylon <NUM> melt <NUM>-50wt%.

A melt-spinning method of nylon <NUM> polymer as described above, the polymer chips being one or more of polyester, nylon, and polyethylene glycol.

A melt-spinning method of nylon <NUM> polymer as described above, Polyester is one or more of polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, and water-soluble polyester; Nylon is one or more of nylon <NUM>, nylon 6T, nylon <NUM>, nylon <NUM>, nylon <NUM>, nylon <NUM>, nylon <NUM>, nylon <NUM>, nylon <NUM>, nylon <NUM>, nylon <NUM>; Polyethylene glycol has a molecular weight in the range of <NUM>-<NUM>, The polyethylene glycol is either the hydroxyl group or the polyethylene glycol, which is modified to be a spindle or amino group.

The invention also provides a method of a nylon <NUM> polymer spun into fibers and woven fabric. Nylon <NUM> fiber is made by spinning the nylon polymer and then woven or knitted to form a fabric which is one of plain, twill and satin and then dyed to obtain fabrics of different specifications and colors.

Fabric as mentioned above, the dyeing process of the fabric is as follows: Pretreatment desizing-Hot water cleaning fabric-Heat up the dyeing-Fix color-Cooling cleaning-Fabric out of the water stereotypes-Product testing-Finished roll.

Fabric as mentioned above, the pretreatment of desizing temperature is <NUM>-<NUM>, the desizing time is <NUM>-<NUM>, and its desizing agent is used. The formula is: pure alkali <NUM>-<NUM>/L, degreaser <NUM>-<NUM>/L.

Fabric as mentioned above, the temperature dyeing process is: the initial dyeing temperature is <NUM>-<NUM>, the rate of heating is <NUM>-<NUM> C/min, heating to <NUM>-<NUM> and heat preservation for <NUM>. The concentration of dye is <NUM>-<NUM>(omf), and the bath ratio is <NUM>:<NUM>-<NUM>.

Fabric as mentioned above, The fixing process for solid color temperature is <NUM>-<NUM>, time is <NUM>-<NUM>, The concentration of fixing agent is <NUM>-<NUM>%(omf) and the bath ratio is <NUM>:<NUM>-<NUM>.

Fabric as mentioned above, in the dyeing and fixing process, appropriate to add some additives, the adding amount is <NUM>-<NUM>/L, the assistant is NORM02, which belongs to water softener. The leveling agent is ACD03 or ACD16. The retarding agent is ammonium sulfate.

The invention provides a nylon <NUM> polymerization device, the function of the silo is to store the hexephthalamide, which is connected to the heating tank of the raw material through the pipe. The function of the heating tank is to melt the caprolactam, and the pressurized open loop cauldron is connected to the heating tank of the raw material through the pipe. Pressurized open loop cauldron role is through the pressure to promote the hydrolysis of caprolactam open-loop to obtain cyclic oligomers with low content of prepolymer. The polycondensation kettle is connected with the pressurized open-loop kettle through the pipeline. The role of the polycondensation kettle is the precondensation of the product of the pressurized open-loop kettle to molecular weight near the molecular chain entanglement point, and a large number of unreacted monomer is removed, at this point the melt viscosity is lower, so the conditions of condensation are not high. The liquid thickener is connected with the polycondensation reactor through a pipeline. The role of liquid phase thickening kettle is the polycondensation kettle product by high vacuum polycondensation reaction kinetics enhanced to the target molecular weight, and the unreacted monomer and water quickly extracted, in this case the melt viscosity is high, so the polycondensation conditions require high. Polycondensation reactor, liquid-phase tackifying kettle are respectively connected with the buffer tank through the pipeline, the role of the buffer tank is to collect the small molecules extracted by polycondensation kettle and liquid thickener, and transport it to the concentration tank. The concentrator and the buffer tank are connected through the pipeline. The function of the concentrated tank is to concentrate the monomer conveyed in the buffer tank and redistribute it to the heating tank of the raw material and continue to participate in the reaction. The concentrate sent to the concentrator is reused. The obtained melt is directly transported to the spinning component for spinning, then weaving, dyeing and finishing, and getting the final product.

The present invention adopts low-temperature polymerization to prepare a prepolymer and realizes effective control of the cyclic dimer, mainly relying on the following mechanism: The reactions occurring during the hydrolyzation of caprolactam are reversible equilibrium reactions. The reaction to form a cyclic dimer is mainly an amino-terminal occlusion reaction, and its reaction can be expressed by the following equation:<MAT>.

Among them, the positive reaction is a cyclic dimer ring-opening addition reaction, and the activation energy is Ea1=<NUM>. 12KJ/mol; The reverse reaction is an amino-terminal occlusion reaction. The activation energy of the reaction is Ea2=<NUM> KJ/mol, which is the most important way to form a cyclic dimer.

Temperature is the most important factor affecting oligomer content in caprolactam polymerization system. The following formula is Arrhenius formula:
<MAT>.

From above, the relationship between reaction rate constant k and temperature can be obtained, as can be seen from the formula, the higher the activation energy of the reaction, the more sensitive the reaction rate constant to the temperature change, and the activation energy of the addition polymerization of the cyclic dimer is less than the activation energy of the ring formation reaction. Therefore, polymerization temperature, is advantageous to the cyclization reaction, so that the levels of low molecular material are increased.

<NUM>: silo; <NUM>: valve; <NUM>: raw material heating tank; <NUM>: pressurized open-loop kettle; <NUM>: polycondensation kettle; <NUM>: liquid phase thickening kettle; <NUM>: buffer tank;.

Hereinafter, the present invention will be described in more detail by the following examples. It should be noticed that these examples are only for illustrating the present invention and are not intended to limit the scope of the present invention. In addition, it should be noticed that after reading the content of the present invention, those skilled in this field can make various modifications or changes to the present invention, and these equivalent forms also apply to the scope of the appended claims of this application.

A nylon <NUM> polymerization method is prepared by a stepwise polymerization method, and the specific preparation method is as follows:.

The nylon <NUM> polymer of Example <NUM> is directly spun according to the nylon <NUM> spinning process after the kinetic strengthening process of the polycondensation reaction, the spinning temperature is <NUM>, the first godet speed is <NUM> / min, and the second the godet speed is <NUM>/min, the draw ratio is <NUM> times, the cooling air temperature is <NUM>, the wind speed is <NUM>/s, and the relative humidity is <NUM>%, and the fully drawn yarn is obtained.

The spinning microporous cross-sectional shape of the above spinning is a triangle;
After the completion of the kinetic strengthening process of the polycondensation reaction, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, the amount of addition is <NUM> wt% of nylon <NUM> polymer. The matrix of the functional masterbatch or masterbatch is nylon <NUM>. The functional adjuvant contained in the functional masterbatch is an antioxidant <NUM> in an amount of <NUM>% by weight of the functional masterbatch. The colorant used in the masterbatch is phthalocyanine red.

After the nylon <NUM> polymer is finished at the end of the polycondensation reaction kinetic strengthening process, the polymer chips are added on-line during the melt transfer process, and immediately mixed and directly spun according to the nylon <NUM> spinning process, and the amount of the polymer chips added is <NUM> wt% of the nylon <NUM> melt. The polymer slice is polyethylene terephthalate.

The nylon <NUM> polymer of Example <NUM> is directly spun according to the nylon <NUM> spinning process after the end of the polycondensation reaction kinetic strengthening process, the spinning temperature is <NUM>, the first godet speed is <NUM> / min, and the second godet speed is <NUM>/min, the draw ratio is <NUM> times, the cooling air temperature is <NUM>, the wind speed is <NUM>/s, and the relative humidity is <NUM>%, and the fully drawn yarn is obtained.

The spinning microporous cross-sectional shape of the above spinning is a cross shape;
After the completion of the kinetic strengthening process of the polycondensation reaction, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, the amount of addition is <NUM>% by weight of nylon <NUM> polymer. The matrix of the functional masterbatch or masterbatch is nylon 6T. The functional adjuvant contained in the functional masterbatch is an antioxidant <NUM> in an amount of <NUM>% by weight of the functional masterbatch. The colorant used in the masterbatch is phthalocyanine blue.

After the nylon <NUM> polymer is finished at the end of the polycondensation reaction kinetic strengthening process, the polymer chips are added on-line during the melt transfer process, and immediately mixed and directly spun according to the nylon <NUM> spinning process, and the amount of the polymer chips added is <NUM>% by weight of the nylon <NUM> melt. The polymer section is nylon <NUM>.

The spinning microporous cross-sectional shape of the above spinning is polygonal;
After the completion of the kinetic strengthening process of the polycondensation reaction, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, the amount of addition is <NUM> wt% of nylon <NUM> polymer. The matrix of the functional masterbatch or masterbatch is nylon <NUM> and polyethylene terephthalate. The functional adjuvant contained in the functional masterbatch is an antioxidant <NUM> in an amount of <NUM>% by weight of the functional masterbatch. The colorant used in the masterbatch is phthalocyanine green.

After the nylon <NUM> polymer is finished at the end of the polycondensation reaction kinetic strengthening process, the polymer chips are added on-line during the melt transfer process, and immediately mixed and directly spun according to the nylon <NUM> spinning process, and the amount of the polymer chips added is <NUM>% by weight of the nylon <NUM> melt. The polymer section is polyethylene glycol (polyethylene glycol has a molecular weight of <NUM> and polyethylene glycol end groups are hydroxyl groups).

Example <NUM> does not fall within the scope of the claimed invention but may be useful in understanding the invention.

The nylon <NUM> polymer of Example <NUM> is directly spun according to the nylon <NUM> spinning process after the end of the polycondensation reaction kinetic strengthening process, the spinning temperature is <NUM>, the first godet speed is <NUM> / min, and the second The godet speed is <NUM>/min, the draw ratio is <NUM> times, the cooling air temperature is <NUM>, the wind speed is <NUM>/s, and the relative humidity is <NUM>%, and the fully drawn yarn is obtained.

The spinning microporous cross-sectional shape of the above spinning is hollow fiber;
After the completion of the kinetic strengthening process of the polycondensation reaction, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, the amount of addition is <NUM>% by weight of nylon <NUM> polymer. The matrix of the functional masterbatch or masterbatch is nylon <NUM> and polybutylene terephthalate. The functional adjuvant contained in the functional masterbatch is an anti-UV agent salicylic acid in an amount of <NUM>% by weight of the functional masterbatch. The colorant used in the masterbatch is light fast red.

After the nylon <NUM> polymer is finished at the end of the polycondensation reaction kinetic strengthening process, the polymer chips are added on-line during the melt transfer process, and immediately mixed and directly spun according to the nylon <NUM> spinning process, and the amount of the polymer chips added is <NUM>% by weight of the nylon <NUM> melt. The polymer chips are polybutylene terephthalate and nylon 6T.

The nylon <NUM> polymer of Example <NUM> is directly spun in accordance with the nylon <NUM> spinning process after the kinetic strengthening process of the polycondensation reaction, the spinning temperature is <NUM>, the spinning speed is <NUM> / min, and the cooling air temperature is <NUM>. °C, wind speed of <NUM> / s, relative humidity of <NUM>%, to obtain unoriented yarn.

The spinning microporous cross-sectional shape of the above spinning is U-shaped;
After the completion of the kinetic strengthening process of the polycondensation reaction, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, the amount of addition is <NUM>% by weight of nylon <NUM> polymer. The matrix of the functional masterbatch or masterbatch is polytrimethylene terephthalate. The functional auxiliary contained in the functional masterbatch is an anti-UV agent benzophenone-based benzotriazole system in an amount of <NUM> wt% of the functional masterbatch. The colorant used in the masterbatch is macromolecular red.

After the nylon <NUM> polymer is finished at the end of the polycondensation reaction kinetic strengthening process, the polymer chips are added on-line during the melt transfer process, and immediately mixed and directly spun according to the nylon <NUM> spinning process, and the amount of the polymer chips added is <NUM>% by weight of the nylon <NUM> melt. The polymer chips are nylon <NUM> and polyethylene glycol (polyethylene glycol having a molecular weight of <NUM>,<NUM> and a modified terminal group being a carboxyl group).

The nylon <NUM> polymer of Example <NUM> is directly spun according to the nylon <NUM> spinning process after the kinetic strengthening process of the polycondensation reaction, the spinning temperature is <NUM>, the spinning speed is <NUM> / min, and the cooling air temperature is <NUM>, wind speed <NUM> / s, relative humidity of <NUM>%, to obtain unoriented yarn.

The spinning microporous cross-sectional shape of the above spinning is T-shaped;
After the completion of the kinetic strengthening process of the polycondensation reaction, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, the amount of addition is <NUM> wt% of nylon <NUM> polymer. The matrix of the functional masterbatch or masterbatch is nylon <NUM> and a water soluble polyester. The functional additive contained in the functional masterbatch is an anti-UV agent talc powder in an amount of <NUM>% by weight of the functional masterbatch. The colorant used in the masterbatch is macromolecular yellow.

After the nylon <NUM> polymer is finished at the end of the polycondensation reaction kinetic strengthening process, the polymer chips are added on-line during the melt transfer process, and immediately mixed and directly spun according to the nylon <NUM> spinning process, and the amount of the polymer chips added is <NUM> wt% of the nylon <NUM> melt. The polymer slice is polytrimethylene terephthalate.

The nylon <NUM> polymer of Example <NUM> is directly spun according to the nylon <NUM> spinning process at the end of the kinetic strengthening process of the polycondensation reaction, the spinning temperature is <NUM>, the spinning speed is <NUM>/min, and the cooling air temperature is <NUM>, wind speed <NUM> / s, relative humidity of <NUM>%, to obtain unoriented yarn.

The spinning microporous cross-sectional shape of the above spinning is Y-shaped;
After the completion of the kinetic strengthening process of the polycondensation reaction, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, the amount of addition is <NUM>% by weight of nylon <NUM> polymer. The matrix of the functional masterbatch or masterbatch is polyethylene glycol (molecular weight <NUM>, polyethylene glycol end groups are hydroxyl groups). The functional additive contained in the functional masterbatch is an anti-UV agent calcium carbonate in an amount of <NUM>% by weight of the functional masterbatch. The colorant used in the masterbatch is permanent yellow.

After the nylon <NUM> polymer is finished at the end of the polycondensation reaction kinetic strengthening process, the polymer chips are added on-line during the melt transfer process, and immediately mixed and directly spun according to the nylon <NUM> spinning process, and the amount of the polymer chips added is <NUM>% by weight of the nylon <NUM> melt. The polymer slice is nylon <NUM>.

The nylon <NUM> polymer of Example <NUM> is directly spun according to the nylon <NUM> spinning process after the end of the polycondensation reaction kinetic strengthening process, the spinning temperature is <NUM>, the spinning speed is <NUM> / min, and the cooling air temperature is <NUM>, wind speed <NUM> / s, relative humidity of <NUM>%, to obtain unoriented yarn.

The spinning microporous cross-sectional shape of the above spinning is a polygon;
After the completion of the kinetic strengthening process of the polycondensation reaction, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, the amount of addition is <NUM>% by weight of nylon <NUM> polymer. The matrix of the functional masterbatch or masterbatch is nylon <NUM> and polyethylene glycol (molecular weight <NUM>,<NUM>, polyethylene glycol end groups are hydroxyl groups). The functional adjuvant contained in the functional masterbatch is an antibacterial agent nano-titanium dioxide in an amount of <NUM>% by weight of the functional masterbatch. The colorant used in the masterbatch is Pigment Red <NUM>.

After the nylon <NUM> polymer is finished at the end of the polycondensation reaction kinetic strengthening process, the polymer chips are added on-line during the melt transfer process, and immediately mixed and directly spun according to the nylon <NUM> spinning process, and the amount of the polymer chips added is <NUM> wt% of the nylon <NUM> melt. The polymer chip is polyethylene glycol (polyethylene glycol having a molecular weight of <NUM> modified end group amino group).

The nylon <NUM> polymer of Example <NUM> is directly spun according to the nylon <NUM> spinning process after the kinetic strengthening process of the polycondensation reaction, the spinning temperature is <NUM>, the spinning speed is <NUM>/min, and the cooling air temperature is <NUM>, wind speed of <NUM> / s, relative humidity of <NUM>%, to obtain pre-oriented yarn.

The spinning microporous cross-sectional shape of the above spinning is in an I-shape;
After the completion of the kinetic strengthening process of the polycondensation reaction, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, the amount of addition is <NUM>% by weight of nylon <NUM> polymer. The matrix of the functional masterbatch or masterbatch is nylon <NUM>. The functional auxiliary contained in the functional masterbatch is zinc oxide, an antibacterial agent, in an amount of <NUM>% by weight of the functional masterbatch. The colorant used in the masterbatch is Pigment Blue <NUM>.

After the nylon <NUM> polymer is finished at the end of the polycondensation reaction kinetic strengthening process, the polymer chips are added on-line during the melt transfer process, and immediately mixed and directly spun according to the nylon <NUM> spinning process, and the amount of the polymer chips added is <NUM>% by weight of the nylon <NUM> melt. The polymer chip is a water-soluble polyester.

The nylon <NUM> polymer of Example <NUM> is directly spun according to the nylon <NUM> spinning process after the kinetic strengthening process of the polycondensation reaction, the spinning temperature is <NUM>, the spinning speed is <NUM>/min, and the cooling air temperature is <NUM>, wind speed <NUM> / s, relative humidity of <NUM>%, to obtain pre-oriented yarn.

The spinning microporous cross-sectional shape of the above spinning is a triangle;
After the completion of the kinetic strengthening process of the polycondensation reaction, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, the amount of addition is <NUM>% by weight of nylon <NUM> polymer. The matrix of the functional masterbatch or masterbatch is branched nylon. The functional additive contained in the functional masterbatch is an antibacterial agent iron oxide in an amount of <NUM>% by weight of the functional masterbatch. The colorant used in the masterbatch is Solvent Violet <NUM>.

After the nylon <NUM> polymer is finished at the end of the polycondensation reaction kinetic strengthening process, the polymer chips are added on-line during the melt transfer process, and immediately mixed and directly spun according to the nylon <NUM> spinning process, and the amount of the polymer chips added is <NUM> wt% of the nylon <NUM> melt. The polymer section is nylon <NUM>.

The nylon <NUM> polymer of Example <NUM> is directly spun according to the nylon <NUM> spinning process after the kinetic strengthening process of the polycondensation reaction, the spinning temperature is <NUM>, the spinning speed is <NUM> / min, and the cooling air temperature is <NUM>, wind speed of <NUM> / s, relative humidity of <NUM>%, to obtain pre-oriented yarn.

The spinning microporous cross-sectional shape of the above spinning is a cross shape;
After the completion of the kinetic strengthening process of the polycondensation reaction, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, the amount of addition is <NUM> wt% of nylon <NUM> polymer. The matrix of the functional masterbatch or masterbatch is polyethylene terephthalate. The functional auxiliary agent contained in the functional masterbatch is a quaternary ammonium salt compound, wherein R1, R2=C8, R1 and R2 are the same; X- is Cl-, and the content is <NUM>% by weight of the functional masterbatch. The colorant used in the masterbatch is Solvent Red <NUM>.

After the nylon <NUM> polymer is finished at the end of the polycondensation reaction kinetic strengthening process, the polymer chips are added on-line during the melt transfer process, and immediately mixed and directly spun according to the nylon <NUM> spinning process, and the amount of the polymer chips added is <NUM>% by weight of the nylon <NUM> melt. The polymer chips are polytrimethylene terephthalate and a water soluble polyester.

The nylon <NUM> polymer of Example <NUM> is directly spun according to the nylon <NUM> spinning process after the end of the polycondensation reaction kinetic strengthening process, the spinning temperature is <NUM>, the spinning speed is <NUM> / min, and the cooling air temperature is <NUM>, wind speed <NUM> / s, relative humidity of <NUM>%, to obtain pre-oriented yarn.

The spinning microporous cross-sectional shape of the above spinning is polygonal;
After the completion of the kinetic strengthening process of the polycondensation reaction, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, the amount of addition is <NUM>% by weight of nylon <NUM> polymer. The matrix of the functional masterbatch or masterbatch is nylon <NUM>. The functional auxiliary agent contained in the functional masterbatch is a quaternary ammonium salt compound, wherein R1, R2=C20, R1 and R2 are the same; X- is Br-, and the content is <NUM> wt% of the functional masterbatch. The colorant used in the masterbatch is Solvent Blue <NUM>.

The nylon <NUM> polymer of Example <NUM> is directly spun according to the nylon <NUM> spinning process after the kinetic strengthening process of the polycondensation reaction, the spinning temperature is <NUM>, the spinning speed is <NUM>/min, and the cooling air temperature is <NUM>, wind speed <NUM> / s, relative humidity of <NUM>%, to obtain highly oriented filaments.

The spinning microporous cross-sectional shape of the above spinning is hollow fiber;
After the completion of the kinetic strengthening process of the polycondensation reaction, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, the amount of addition is <NUM>% by weight of nylon <NUM> polymer. The matrix of the functional masterbatch or masterbatch is polybutylene terephthalate. The functional auxiliary contained in the functional masterbatch is a flame retardant zinc borate at a content of <NUM>% by weight of the functional masterbatch. The colorant used in the masterbatch is Solvent Green <NUM>.

The nylon <NUM> polymer of Example <NUM> is directly spun according to the nylon <NUM> spinning process after the kinetic strengthening process of the polycondensation reaction, the spinning temperature is <NUM>, the spinning speed is <NUM> / min, and the cooling air temperature is <NUM>, wind speed of <NUM> / s, relative humidity of <NUM>%, to obtain highly oriented filaments.

The spinning microporous cross-sectional shape of the above spinning is U-shaped;
After the completion of the kinetic strengthening process of the polycondensation reaction, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, the amount of addition is <NUM> wt% of nylon <NUM> polymer. The matrix of the functional masterbatch or masterbatch is nylon <NUM>. The functional auxiliary contained in the functional masterbatch is a flame retardant ammonium polyphosphate, and the content is <NUM>% by weight of the functional masterbatch. The colorant used in the masterbatch is Solvent Yellow <NUM>.

After the nylon <NUM> polymer is finished at the end of the polycondensation reaction kinetic strengthening process, the polymer chips are added on-line during the melt transfer process, and immediately mixed and directly spun according to the nylon <NUM> spinning process, and the amount of the polymer chips added is <NUM>% by weight of the nylon <NUM> melt. The polymer chips are nylon <NUM> and nylon <NUM>.

The spinning microporous cross-sectional shape of the above spinning is T-shaped;
After the completion of the kinetic strengthening process of the polycondensation reaction, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, the amount of addition is <NUM>% by weight of nylon <NUM> polymer. The matrix of the functional masterbatch or masterbatch is nylon <NUM>. The functional auxiliary contained in the functional masterbatch is a mixture of <NUM>,<NUM>,<NUM>-tris(<NUM>,<NUM>-diamino-<NUM>-thiotriazine)hexane and cyanuric acid, and the content is functional. <NUM>% by weight of the masterbatch. The colorants used in the masterbatch are Solvent Yellow <NUM> and Pigment Red <NUM>.

After the nylon <NUM> polymer is finished at the end of the polycondensation reaction kinetic strengthening process, the polymer chips are added on-line during the melt transfer process, and immediately mixed and directly spun according to the nylon <NUM> spinning process, and the amount of the polymer chips added is <NUM>% by weight of the nylon <NUM> melt. The polymer section is nylon nylon <NUM>.

The spinning microporous cross-sectional shape of the above spinning is Y-shaped;
After the completion of the kinetic strengthening process of the polycondensation reaction, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, the amount of addition is <NUM> wt% of nylon <NUM> polymer. The matrix of the functional masterbatch or masterbatch is polytrimethylene terephthalate. The functional additive contained in the functional masterbatch is an anion generating material, kiwi, in an amount of <NUM>% by weight of the functional masterbatch. The colorants used in the masterbatch are Solvent Yellow <NUM> and Solvent Yellow <NUM>.

After the nylon <NUM> polymer is finished at the end of the polycondensation reaction kinetic strengthening process, the polymer chips are added on-line during the melt transfer process, and immediately mixed and directly spun according to the nylon <NUM> spinning process, and the amount of the polymer chips added is <NUM> wt% of the nylon <NUM> melt. The polymer section is polyethylene glycol (molecular weight <NUM>,<NUM>, polyethylene glycol end group is hydroxyl group).

The nylon <NUM> polymer of Example <NUM> is directly spun in accordance with the nylon <NUM> spinning process to obtain a puffed textured yarn after the completion of the kinetic strengthening process of the polycondensation reaction. The spinning temperature is <NUM>, the cooling air temperature is <NUM>, and the wind speed is <NUM>. m/s, relative humidity is <NUM>%, feed roller temperature is <NUM>, stretching roll temperature is <NUM>, feed speed is <NUM> / min, tensile speed is <NUM> / min, draw ratio is <NUM> times, deformation The hot air temperature is <NUM>, the air injection pressure is <NUM> kPa, the winding speed is <NUM>/min, and the cooling air temperature is <NUM>.

The spinning microporous cross-sectional shape of the above spinning is a polygon;
After the completion of the kinetic strengthening process of the polycondensation reaction, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, the amount of addition is <NUM>% by weight of nylon <NUM> polymer. The matrix of the functional masterbatch or masterbatch is polytrimethylene terephthalate and a water soluble polyester. The functional additive contained in the functional masterbatch is a negative ion generating material tourmaline in an amount of <NUM>% by weight of the functional masterbatch. The colorant used in the masterbatch is Solvent Violet <NUM>.

After the nylon <NUM> polymer is finished at the end of the polycondensation reaction kinetic strengthening process, the polymer chips are added on-line during the melt transfer process, and immediately mixed and directly spun according to the nylon <NUM> spinning process, and the amount of the polymer chips added is <NUM>% by weight of the nylon <NUM> melt. The polymer slice is polybutylene terephthalate.

The nylon <NUM> polymer of Example <NUM> is directly spun in accordance with the nylon <NUM> spinning process to obtain a puffed textured yarn after the completion of the kinetic strengthening process of the polycondensation reaction. The spinning temperature is <NUM>, the cooling air temperature is <NUM>, and the wind speed is <NUM>. / s, relative humidity is <NUM>%, feed roller temperature is <NUM>, stretching roller temperature is <NUM>, feeding speed is <NUM> / min, stretching speed is <NUM> / min, stretching ratio is <NUM> times, heat of deformation The air temperature is <NUM>, the air injection pressure is <NUM> kPa, the winding speed is <NUM>/min, and the cooling air temperature is <NUM>.

The spinning microporous cross-sectional shape of the above spinning is in an I-shape;
After the completion of the kinetic strengthening process of the polycondensation reaction, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, the amount of addition is <NUM> wt% of nylon <NUM> polymer. The matrix of the functional masterbatch or masterbatch is nylon <NUM>. The functional auxiliary agent contained in the functional masterbatch is a fluorescent material (using an alkaline earth metal sulfide or an aluminate as a light-emitting substrate, and a rare earth lanthanide lanthanum, cerium, lanthanum or cerium as an activator). It is <NUM>% by weight of the functional masterbatch. The colorant used in the masterbatch is Solvent Red <NUM>.

After the nylon <NUM> polymer is finished at the end of the polycondensation reaction kinetic strengthening process, the polymer chips are added on-line during the melt transfer process, and immediately mixed and directly spun according to the nylon <NUM> spinning process, and the amount of the polymer chips added is <NUM> wt% of the nylon <NUM> melt. The polymer chip is a water soluble polyester.

The spinning microporous cross-sectional shape of the above spinning is a triangle;
After the completion of the kinetic strengthening process of the polycondensation reaction, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, the amount of addition is <NUM>% by weight of nylon <NUM> polymer. The matrix of the functional masterbatch or masterbatch is nylon 6T. The functional auxiliary contained in the functional masterbatch is an anion generating material opal in an amount of <NUM> wt% of the functional masterbatch. The colorant used in the masterbatch is Solvent Blue <NUM>.

After the nylon <NUM> polymer is finished at the end of the polycondensation reaction kinetic strengthening process, the polymer chips are added on-line during the melt transfer process, and immediately mixed and directly spun according to the nylon <NUM> spinning process, and the amount of the polymer chips added is <NUM>% by weight of the nylon <NUM> melt. The polymer slice is polytrimethylene terephthalate.

The spinning microporous cross-sectional shape of the above spinning is a cross shape;
After the completion of the kinetic strengthening process of the polycondensation reaction, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, the amount of addition is <NUM>% by weight of nylon <NUM> polymer. The matrix of the functional masterbatch or masterbatch is nylon <NUM>. The functional auxiliary contained in the functional masterbatch is an anion generating material genius stone in an amount of <NUM>% by weight of the functional masterbatch. The colorant used in the masterbatch is carbon black.

After the nylon <NUM> polymer is finished at the end of the polycondensation reaction kinetic strengthening process, the polymer chips are added on-line during the melt transfer process, and immediately mixed and directly spun according to the nylon <NUM> spinning process, and the amount of the polymer chips added is <NUM> wt% of the nylon <NUM> melt. The polymer slice is polybutylene terephthalate.

The nylon <NUM> polymer described in Example <NUM> is directly applied to the composite spinning after the end of the polycondensation reaction kinetic strengthening process, and the composite spinning is a side-by-side type, and the other component of the composite spinning except nylon <NUM> is Nylon 6T, the mass ratio of the nylon <NUM> polymer to the other component is <NUM>:<NUM>.

The spinning microporous cross-sectional shape of the above spinning is polygonal;
After the completion of the kinetic strengthening process of the polycondensation reaction, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, the amount of addition is <NUM> wt% of nylon <NUM> polymer. The matrix of the functional masterbatch or masterbatch is polytrimethylene terephthalate. The functional auxiliary contained in the functional masterbatch is a flame retardant bis(hexachlorocyclopentadienyl)cyclooctane in an amount of <NUM>% by weight of the functional masterbatch. The colorant used in the masterbatch is Pigment Yellow <NUM>.

The nylon <NUM> polymer of Example <NUM> is directly applied to the composite spinning after the end of the polycondensation reaction kinetic strengthening process, and the composite spinning is an island-in-the-sea type; the other component of the composite spinning except nylon <NUM> is Nylon <NUM>, the mass ratio of the nylon <NUM> polymer to the other component is <NUM>:<NUM>.

The spinning microporous cross-sectional shape of the above spinning is hollow fiber;
After the completion of the kinetic strengthening process of the polycondensation reaction, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, the amount of addition is <NUM>% by weight of nylon <NUM> polymer. The matrix of the functional masterbatch or masterbatch is nylon <NUM>. The functional auxiliary contained in the functional masterbatch is the flame retardant decabromodiphenyl ether in an amount of <NUM>% by weight of the functional masterbatch. The colorant used in the masterbatch is iron oxide red.

After the nylon <NUM> polymer is finished at the end of the polycondensation reaction kinetic strengthening process, the polymer chips are added on-line during the melt transfer process, and immediately mixed and directly spun according to the nylon <NUM> spinning process, and the amount of the polymer chips added is <NUM>% by weight of the nylon <NUM> melt. The polymer chip is a water soluble polyester.

The nylon <NUM> fiber obtained by spinning the nylon polymer described in Example <NUM> is then woven into a fabric, which is plain, and then dyed to obtain a cloth of different specifications.

The dyeing production process of the fabric is: pre-treatment desizing-hot water cleaning fabric-heating dyeing-fixing color-cooling cleaning-fabric machine waterproof stereotype-finished product inspection-finished product rolling.

The pretreatment desizing temperature is <NUM>, the desizing time is <NUM>, and the desizing aid formula is: soda ash <NUM> / L, deoiling spirit <NUM> / L.

The temperature rising dyeing process is a temperature of <NUM> at the initial dyeing temperature, a temperature increase of <NUM> / min, and the temperature is raised to <NUM> for another <NUM>; the concentration of the dye is <NUM>% (omf), and the bath ratio is <NUM>:<NUM>.

The fixing process is a temperature of <NUM>, a fixing time of <NUM>, a fixing agent concentration of <NUM>% (omf), and a bath ratio of <NUM>:<NUM>.

In the process of dyeing and fixing, an auxiliary agent is added, and the auxiliary agent is added in an amount of <NUM>/L, and the auxiliary agent includes a water softener NORM02, a leveling agent ACID03, and a retarding agent ammonium sulfate.

The nylon <NUM> fiber obtained by spinning the nylon polymer described in Example <NUM> is then knitted to form a fabric which is twill and then dyed to obtain a cloth of different specifications.

The temperature rising dyeing process is that the initial dyeing temperature is <NUM>, the temperature is raised at a rate of <NUM> / min, the temperature is raised to <NUM> and then kept for <NUM>; the dye concentration is <NUM>% (omf), and the bath ratio is <NUM>:<NUM>.

In the dyeing and fixing process, an auxiliary agent is added, and the auxiliary agent is added in an amount of <NUM>/L, and the auxiliary agent includes a water softener NORM02, a leveling agent ACID <NUM>, and a retarding agent ammonium sulfate.

The nylon <NUM> fiber obtained by spinning the nylon polymer described in Example <NUM> is then woven into a fabric which is satin-printed and then dyed to obtain a cloth of different specifications.

The temperature rising dyeing process is that the initial dyeing temperature is <NUM>, the temperature is raised at a rate of <NUM> / min, the temperature is raised to <NUM> and then kept for <NUM>; the concentration of the dye is <NUM>% (omf), and the bath ratio is <NUM>:<NUM>.

In the dyeing and fixing process, an auxiliary agent is added, and the auxiliary agent is added in an amount of <NUM>/L, and the auxiliary agent includes a water softener NORM02, a leveling agent ACID03, and a retarding agent ammonium sulfate.

The nylon <NUM> fiber obtained by spinning the nylon polymer described in Example <NUM> is then knitted to form a fabric which is plain and then dyed to obtain a cloth of different specifications.

The pretreatment desizing temperature is <NUM>, the desizing time is <NUM>, and the desizing assistant formula is: soda ash <NUM> / L, deoiling spirit <NUM> / L.

The temperature rising dyeing process has a dyeing temperature of <NUM>, a temperature increase of <NUM> / min, a temperature increase of <NUM> and a temperature of <NUM>; a dye concentration of <NUM>% (omf), a bath ratio of <NUM>:<NUM>.

In the process of dyeing and fixing, an auxiliary agent is added, and the auxiliary agent is added in an amount of <NUM>-<NUM>/L, and the auxiliary agent includes a softener NORM02, a leveling agent ACID <NUM>, and a retarding agent ammonium sulfate.

As shown in <FIG>, a device for a nylon <NUM> polymerization method, the silo <NUM> functions to store caprolactam, which is connected to a raw material heating tank <NUM> through a pipe, and the raw material heating tank <NUM> functions to melt caprolactam; <NUM> is connected to the raw material heating tank <NUM> through a pipe, and the function of the pressurized open-loop kettle <NUM> is to promote the hydrolysis and opening of the caprolactam by means of pressurization to obtain a prepolymer having a low cyclic oligomer content; the polycondensation kettle <NUM> passes through the pipeline Connected to the pressurized open-loop kettle <NUM>, the function of the polycondensation tank <NUM> is to pre-condense the product of the pressurized open-loop kettle <NUM> to a molecular weight near the molecular chain entanglement point, and to remove a large amount of unreacted monomers. The melt viscosity is low, so the conditions for polycondensation are not high; the liquid phase thickening kettle <NUM> is connected to the polycondensation vessel <NUM> through a pipe, and the liquid phase thickening kettle <NUM> functions to pass the product of the polycondensation kettle <NUM> through high vacuum polycondensation reaction power. Learn to strengthen to the target molecular weight, and quickly remove unreacted monomer and water, at this time the melt viscosity is higher, so the conditions for polycondensation are high; in the polycondensation kettle <NUM>, the liquid phase thickening kettle <NUM> and the buffer tank <NUM> connected by pipes, buffer tank <NUM> The function is to collect the small molecules extracted from the polycondensation kettle <NUM> and the liquid phase thickening kettle <NUM>, and transport them to the concentration tank <NUM>; the concentration tank <NUM> and the buffer tank <NUM> are connected by a pipe, and the function of the concentration tank <NUM> is to buffer The monomer conveyed from the tank <NUM> is concentrated and re-delivered into the raw material heating tank <NUM> to continue to participate in the reaction. It is sent to a concentrator <NUM> for concentration and property reuse; the resulting melt is directly conveyed to a spinning pack for spinning, followed by weaving, dyeing, and obtaining a final product.

The caprolactam passes through the silo <NUM> to the raw material heating tank <NUM>, and the caprolactam is melted and then sent to the pressurized open-loop kettle <NUM>. After the ring-opening, the prepolymer obtained is sent to the polycondensation vessel <NUM> for vacuum polycondensation, and the obtained polymer is transported. The liquid phase thickening kettle <NUM> is subjected to high vacuum polycondensation, and the obtained melt is directly conveyed to a spinning pack for spinning, followed by weaving and dyeing to obtain a final product. The caprolactam extracted in <NUM>, <NUM> will be sent to a concentrator <NUM> for concentration and property reuse.

The nylon <NUM> polymer of Example <NUM> is directly spun according to the nylon <NUM> spinning process immediately after the end of the liquid phase thickening reaction, the spinning temperature is <NUM>, the spinning speed is <NUM> / min, and the cooling air temperature is <NUM>. The wind speed is <NUM>/s and the relative humidity is <NUM>%, and a pre-oriented yarn is obtained.

The spinning microporous cross-sectional shape of the above spinning is U-shaped;
After the liquid phase thickening reaction is completed, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, and the amount of the nylon is added. <NUM> wt% of the polymer. The matrix of the functional masterbatch or masterbatch is branched nylon. The functional auxiliary contained in the functional masterbatch is carbon nanotubes in an amount of <NUM>% by weight of the functional masterbatch. The colorant used in the masterbatch is Pigment Brown <NUM>.

After the liquid phase thickening reaction of the above nylon <NUM> polymer is completed, the polymer chips are added on-line during the melt transportation, and immediately mixed and directly spun according to the nylon <NUM> spinning process, and the polymer chip is added in a nylon amount. <NUM>% by weight of the melt. The polymer section is nylon <NUM>.

In Example <NUM> the nylon <NUM> polymer is directly spun in a nylon <NUM> spinning process immediately after the liquid phase thickening reaction is completed, the spinning temperature is <NUM>, the spinning speed is <NUM>/min, and the cooling air temperature is <NUM>. The wind speed is <NUM>/s and the relative humidity is <NUM>%, and a pre-oriented yarn is obtained.

The spinning microporous cross-sectional shape of the above spinning is U-shaped;
After the liquid phase thickening reaction is completed, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, and the amount of the nylon is added. <NUM> wt% of the polymer. The matrix of the functional masterbatch or masterbatch is branched nylon. The functional auxiliary contained in the functional masterbatch is graphene in an amount of <NUM>% by weight of the functional masterbatch. The colorant used in the masterbatch is Pigment Yellow <NUM>.

The nylon <NUM> polymer of Example <NUM> is directly spun according to the nylon <NUM> spinning process immediately after the end of the liquid phase thickening reaction, the spinning temperature is <NUM>, the spinning speed is <NUM> / min, and the cooling air temperature is <NUM>. The wind speed is <NUM>/s, and the relative humidity is <NUM>%, and unoriented yarn is obtained.

The spinning microporous cross-sectional shape of the above spinning is T-shaped;
After the liquid phase thickening reaction is completed, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, and the amount of the nylon is added. <NUM> wt% of the polymer. The matrix of the functional masterbatch or masterbatch is nylon <NUM> and a water soluble polyester. The functional additive contained in the functional masterbatch is an anti-UV agent talc powder in an amount of <NUM>% by weight of the functional masterbatch. The colorant used in the masterbatch is permanent violet.

After the liquid phase thickening reaction of the above nylon <NUM> polymer is completed, the polymer chips are added on-line during the melt transportation, and immediately mixed and directly spun according to the nylon <NUM> spinning process, and the polymer chip is added in a nylon amount. <NUM>% by weight of the melt. The polymer slice is polytrimethylene terephthalate.

The nylon <NUM> polymer of Example <NUM> is directly spun according to the nylon <NUM> spinning process immediately after the end of the liquid phase thickening reaction, the spinning temperature is <NUM>, the spinning speed is <NUM> / min, and the cooling air temperature is <NUM>. The wind speed is <NUM>/s and the relative humidity is <NUM>%, and unoriented yarn is obtained.

The spinning microporous cross-sectional shape of the above spinning is Y-shaped;
After the liquid phase thickening reaction is completed, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, and the amount of the nylon is added. <NUM> wt% of the polymer. The matrix of the functional masterbatch or masterbatch is polyethylene glycol (molecular weight <NUM>, polyethylene glycol end groups are hydroxyl groups). The functional additive contained in the functional masterbatch is an anti-UV agent calcium carbonate in an amount of <NUM>% by weight of the functional masterbatch. The colorants used in the masterbatch are azo red and cadmium red, and the mass ratio of azo red and cadmium red is <NUM>:<NUM>.

After the liquid phase thickening reaction of the above nylon <NUM> polymer is completed, the polymer chips are added on-line during the melt transportation, and immediately mixed and directly spun according to the nylon <NUM> spinning process, and the polymer chip is added in a nylon amount. <NUM><NUM>% by weight of the melt. The polymer slice is nylon <NUM>.

The spinning microporous cross-sectional shape of the above spinning is a polygon;
After the liquid phase thickening reaction is completed, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, and the amount of the nylon is added. <NUM> wt% of the polymer. The matrix of the functional masterbatch or masterbatch is nylon <NUM> and polyethylene glycol (molecular weight <NUM>,<NUM>, polyethylene glycol end groups are hydroxyl groups). The functional adjuvant contained in the functional masterbatch is an antibacterial agent nano-titanium dioxide in an amount of <NUM>% by weight of the functional masterbatch. The colorants used in the masterbatch are cadmium yellow and titanium white powder, and the mass ratio of cadmium yellow and titanium white powder is <NUM>:<NUM>.

After the liquid phase thickening reaction of the above nylon <NUM> polymer is completed, the polymer chips are added on-line during the melt transportation, and immediately mixed and directly spun according to the nylon <NUM> spinning process, and the polymer chip is added in a nylon amount. <NUM><NUM> wt% of the melt. The polymer chip is polyethylene glycol (molecular weight of <NUM>, modified amino group of terminal amino group).

The nylon <NUM> polymer of Example <NUM> is directly spun according to the nylon <NUM> spinning process immediately after the end of the liquid phase thickening reaction, the spinning temperature is <NUM>, the spinning speed is <NUM> / min, and the cooling air temperature is <NUM>. The wind speed is <NUM>/s and the relative humidity is <NUM>% to obtain a pre-oriented yarn.

The spinning microporous cross-sectional shape of the above spinning is a triangle;
After the liquid phase thickening reaction is completed, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, and the amount of the nylon is added. <NUM> wt% of the polymer. The matrix of the functional masterbatch or masterbatch is branched nylon. The functional additive contained in the functional masterbatch is an antibacterial agent iron oxide in an amount of <NUM>% by weight of the functional masterbatch. The colorant used in the masterbatch is iron oxide yellow, pigment green <NUM>, pigment yellow <NUM>, and the mass ratio of iron oxide yellow, pigment green <NUM>, and pigment yellow <NUM> is <NUM>:<NUM>:<NUM>.

The nylon <NUM> polymer of Example <NUM> is directly applied to the composite spinning after the end of the liquid phase thickening reaction, the composite spinning is a side-by-side type, and the other component of the composite spinning except nylon <NUM> is nylon. 6T, the mass ratio of the nylon <NUM> polymer to another component is <NUM>:<NUM>.

The spinning microporous cross-sectional shape of the above spinning is polygonal;
After the liquid phase thickening reaction is completed, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, and the amount of the nylon is added. <NUM> wt% of the polymer. The matrix of the functional masterbatch or masterbatch is polytrimethylene terephthalate. The functional auxiliary contained in the functional masterbatch is a flame retardant bis(hexachlorocyclopentadienyl)cyclooctane in an amount of <NUM>% by weight of the functional masterbatch. The colorants used in the masterbatch are Pigment Orange <NUM> and Pigment Orange <NUM>, and the mass ratio of Pigment Orange <NUM> to Pigment Orange <NUM> is <NUM>:<NUM>.

After the liquid phase thickening reaction of the above nylon <NUM> polymer is completed, the polymer chips are added on-line during the melt transportation, and immediately mixed and directly spun according to the nylon <NUM> spinning process, and the polymer chip is added in a nylon amount. <NUM><NUM>% by weight of the melt. The polymer slice is polybutylene terephthalate.

The spinning microporous cross-sectional shape of the above spinning is polygonal;
After the liquid phase thickening reaction is completed, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, and the amount of the nylon is added. <NUM> wt% of the polymer. The matrix of the functional masterbatch or masterbatch is polytrimethylene terephthalate. The functional auxiliary contained in the functional masterbatch is a flame retardant bis(hexachlorocyclopentadienyl)cyclooctane in an amount of <NUM>% by weight of the functional masterbatch. The colorant used in the masterbatch is Pigment Orange <NUM>.

The spinning microporous cross-sectional shape of the above spinning is a triangle;
After the liquid phase thickening reaction is completed, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, and the amount of the nylon is added. <NUM> wt% of the polymer. The matrix of the functional masterbatch or masterbatch is branched nylon. The functional additive contained in the functional masterbatch is an antibacterial agent iron oxide in an amount of <NUM>% by weight of the functional masterbatch. The colorant used in the masterbatch is iron oxide yellow.

The nylon <NUM> polymer of Example <NUM> is directly spun according to the nylon <NUM> spinning process after the end of the liquid phase thickening reaction, the spinning temperature is <NUM>, the spinning speed is <NUM> / min, and the cooling air temperature is <NUM>. The wind speed is <NUM>/s and the relative humidity is <NUM>% to obtain a pre-oriented yarn.

The spinning microporous cross-sectional shape of the above spinning is a triangle;
After the liquid phase thickening reaction is completed, the above-mentioned nylon <NUM> polymer is added with functional masterbatch or masterbatch in the melt transfer process, and uniformly mixed, and then directly spun according to the nylon <NUM> spinning process, and the amount of the nylon is added. <NUM> wt% of the polymer. The matrix of the functional masterbatch or masterbatch is branched nylon. The functional additive contained in the functional masterbatch is an antibacterial agent iron oxide in an amount of <NUM>% by weight of the functional masterbatch. The colorant used in the masterbatch is Pigment Yellow <NUM>.

Claim 1:
A method for polymerizing nylon <NUM> characterized in that nylon <NUM> is prepared by a stepwise polymerization method, and the specific preparation method is as below:
a first stage ring-opening reaction stage, wherein pre-polymerization is carried out by mixing caprolactam, water and a catalyst at a temperature of <NUM>-<NUM> and at a pressure of <NUM>-<NUM> MPa and over a time of <NUM>-<NUM> hours to obtain a first product;
the obtained first product has a number average molecular weight of <NUM>,<NUM>- <NUM>,<NUM>, an oligomer content of <NUM>-<NUM>%, a cyclic dimer content of less than <NUM>% or less, and a melt viscosity of <NUM>-<NUM> Pa·s;
a second stage pre-polycondensation stage wherein the first product obtained by the ring-opening reaction is subjected to a polycondensation reaction under the conditions of a pressure of <NUM>-<NUM> Pa and a temperature of <NUM>-<NUM> and over a time of <NUM>-<NUM> hours;
the obtained prepolymer of the second stage has a melt molecular weight of <NUM>,<NUM> - <NUM>,<NUM>, and an oligomer content of <NUM>-<NUM>%, wherein the cyclic dimer content is <NUM>%, and the melt viscosity is <NUM> - <NUM> Pa·s;
a third stage being a kinetic strengthening stage polycondensation reaction comprising polymerization under the conditions of a pressure of <NUM>-100Pa, wherein the polymerization temperature is gradually increased from <NUM>-<NUM> to <NUM>-<NUM>, and a polycondensation reaction kinetic strengthening process time is <NUM>-<NUM>;
the obtained melt product of the third stage has a molecular weight of <NUM>,<NUM> - <NUM>,<NUM>, the relative viscosity is <NUM> - <NUM>, and the oligomer content is below <NUM>%, and wherein the cyclic dimer content is <NUM>% or less;
wherein in order to ensure the rapid removal of small molecules for rapid viscosity-increasing purposes, the polymerization temperature is gradually increased from <NUM>-<NUM> to <NUM>-<NUM> as a step heating method to ensure a melt viscosity of <NUM>,<NUM>-<NUM>,<NUM> Pa·s. after the kinetic strengthening of the polycondensation reaction, to obtain a nylon <NUM> polymer.