CN101054737A - Low temperature producing method for nylon fiber - Google Patents

Abstract

The present invention discloses a technology field relating to the preparation method of textile materials, especially to a process for low temperature production of nylon fibre. Said process comprises the steps of adding a chemical compound of the second main group metals during or before nylon melting course and then spinning the obtained molten mass at a low temperature of 160-250 DEG C. Adding auxiliaries of oxidation preventives, ultraviolet absorbents, light-stability agents and anstatic agents therein before the melting course or during the melting course will result in more excellent effects. The method has a lower energy consumption and a lower cost, and its industry operations are more convenient and safe, will find wide use in industries such as garments and intertexture.

Description

A kind of method of producing nylon fiber at low temperature

technical field

The invention relates to the technical field of textile materials, in particular to a method for producing nylon fibers at low temperature.

Background technique

Generally speaking, the polymer materials that can be spun include nylon (polyamide), polypropylene (polypropylene), polyester (polyethylene terephthalate) and acrylic (polyacrylonitrile). These materials can be spun to form filaments for use in the textile industry. Melt spinning is a commonly used spinning method, and fiber filaments suitable for spinning can be obtained by melt spinning. Generally, fiber filaments obtained by the melt spinning method can reach a fineness degree (fineness) of several deniers. The products obtained by weaving and weaving with such fiber filaments, such as clothing fabrics, have many advantages, so the market application space is broad.

Nylon fiber fabric has the characteristics of sweat absorption, light weight, good toughness, good resilience, acid and alkali resistance, etc. It is one of the most suitable artificial fabrics for human wear. The application in clothing is also one of the main uses of nylon fiber.

At present, the industrial production method of nylon fiber is mainly the melt spinning method. In this case, nylon usually needs to be heated to a molten state, and then spun in a molten state (the spinning temperature is generally in the range of 260-280° C.). At this time, in order to keep the nylon in a molten state, it needs to be continuously heated, which will consume a lot of energy, especially the spinneret or spinneret of the spinning equipment, the temperature is generally as high as 280 ° C, and biphenyl is generally used in practice. Heating it, the boiling point of biphenyl is about 265 °, so it is necessary to pressurize to increase the boiling point of biphenyl to avoid its boiling and vaporization, which not only requires high energy consumption, but also requires pressure-resistant equipment. These factors make the production of nylon fibers expensive and demanding in the process using the existing melt spinning method.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for producing nylon fibers at low temperature, which can significantly reduce the energy consumption of nylon fiber production, thereby saving costs.

After a lot of research and experiments, the inventors found that nylon fibers can be spun at a temperature lower than that of existing melt spinning, for example, at a temperature lower than the boiling point of biphenyl.

The application provides a method for producing nylon fibers at low temperature, which is a melt spinning method, including adding a compound of a second main group metal before or during the melting of nylon, and then the resulting melt is heated at 160 to 250°C , preferably at 170 to 230°C, more preferably at a low temperature of 170 to 190°C for spinning.

The term "melt spinning method" in this paper refers to heating and melting the raw materials for spinning, and the molten body is extruded by a screw extruder and then sent to the spinning machine. The spinneret holes on the wire plate flow out the melt in the form of filaments, oiled and wound, or subjected to a hot drawing process to produce fiber filaments.

In the method for producing nylon fibers at low temperature of the present invention, the nylon refers to nylon that can be spun, such as nylon 6, nylon 66, etc., preferably nylon 6.

In the method for producing nylon fibers at low temperature in the present invention, the compound of the second main group metal includes, but not limited to, the second main group metal salt or complex. The second main group metal element is selected from magnesium, calcium, strontium and the like. The anion of the metal salt or the ligand of the complex is selected from phosphate, carbonate, carboxylate, nitrate, sulfate, sulfonate, sulfite, halogen anions (such as fluoride, chloride and bromide, etc. ), pseudohalide ions (eg, thiocyanate), and other nitrogen- and/or oxygen-containing (such as carboxylate) and/or sulfur-containing organic ligands, etc., but are not limited thereto.

Specifically, non-limiting examples of the compounds of the second main group metal include: magnesium carbonate, calcium carbonate, strontium carbonate; magnesium phosphate, calcium phosphate, strontium phosphate; magnesium acetate, calcium acetate, strontium acetate; magnesium sulfate, Calcium Sulfate, Strontium Sulfate; Magnesium Sulfonate, Calcium Sulfonate, Strontium Sulfonate; Magnesium Fluoride, Calcium Fluoride, Strontium Fluoride; Magnesium Chloride, Calcium Chloride, Strontium Chloride; Magnesium Bromide, Calcium Bromide, Bromide strontium etc.

The compound of the second main group metal can reduce the melting point of nylon fiber, and endow the nylon fiber melt with good properties, such as high strength, high viscosity, high spinnability, etc., so it can be obtained at a lower spinning temperature Nylon fibers. The use amount of the compound of the second main group metal is as follows: based on the weight of nylon used, the weight of the second main group metal element in the compound of the second main group metal is 80ppm～10wt%, preferably 0.01wt%～5wt% , more preferably 0.1wt% to 5wt%, particularly preferably 0.3wt% to 2wt%. If the usage amount of the compound of the second main group metal is less than 50 ppm, the modification effect on nylon is not good enough, and it is difficult to obtain nylon fiber at low temperature. If the amount of the compound of the second main group metal is greater than 10 wt%, the added amount of the metal compound will be too much, which will lead to deterioration of the quality of the obtained fiber.

The addition method of the compound of the second main group metal is not particularly limited, it can be added directly, or it can be made into an additive containing the second main group metal with part of nylon and then added, preferably it is combined with part of nylon Additives that form compounds containing metals of the second main group are added.

The method for producing nylon fibers at low temperature of the present invention may also include adding auxiliary agents before or during melting of nylon. The auxiliary agent is, for example, selected from antioxidants, ultraviolet absorbers, light stabilizers and antistatic agents. One or more of these adjuvants may be used.

Wherein, the antioxidants are hindered phenols and phosphites, for example: antioxidant 1010, antioxidant CA, antioxidant 163, antioxidant 168, antioxidant 3114, antioxidant DLTP and antioxidant agent TNP etc. One or more of them can be used. The antioxidant is preferably added in an amount of 0.001 wt% to 1 wt%, based on the weight of the nylon used.

The antioxidants added are: tetrakis[β-(3',5'-di-tert-butyl-4'-hydroxyphenyl) propionate] pentaerythritol ester, 1,1,3-tris(2-methyl-4 -Hydroxy-5-tert-butylphenyl)butane, tris(2,4-di-tert-butylphenyl)phosphite, tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanate, One or more of dilauryl thiodipropionate and trinonylphenyl phosphite.

The ultraviolet absorbers added before or during the melting of nylon are: 2-(2-hydroxy-5-methylphenyl)-benzotriazole, 2-(2-hydroxy-3,5-di-tert-butyl Phenyl)-benzotriazole, 2-(2-hydroxy-5-octylphenyl)-benzotriazole, 2-hydroxy-4-n-octyloxybenzophenone, 2-(2-hydroxy -3,5-di-tert-butylphenyl)-5-chlorobenzotriazole, 2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-5-chlorobenzotriazole One or more of azole, carbon black, zinc oxide, titanium dioxide.

The ultraviolet absorber is organic aromatic substances such as benzotriazoles and benzophenones, such as UV-A, UV-B, UV-320, UV5411, Tinuvin326, Tinuvin 327; inorganic substances such as carbon black, zinc oxide, titanium dioxide, etc. . One or more of them can be used. The added amount of the ultraviolet absorber is preferably 0.001 wt% to 1 wt%, based on the weight of the nylon used.

The light stabilizers are copper halides, hindered amines, phenols, benzophenones, and triazoles. One or more of them can be used. The light stabilizer is preferably added in an amount of 0.001wt%-1wt%, based on the weight of the nylon used.

The antistatic agent is fatty alcohol phosphate, fatty alcohol oxyalkylene ether phosphate salt, fatty alcohol phosphate potassium, lauryl sulfate sodium salt, stearic acid monoglyceride, lauryl alcohol oxyethylene ether phosphate potassium salt , polyethylene glycol, etc. One or more of them can be used. The added amount of the antistatic agent is preferably 0.001wt%-1wt%, based on the weight of the nylon used.

There is no particular limitation on the adding method of the auxiliary agent, it can be added directly, or it can be made into an additive of the second main group metal compound with some nylon and the second main group metal compound and then added.

Like this, in the method for producing nylon fiber at low temperature of the present invention, spinning can be carried out at lower temperature, for example in the temperature range of 160～250 ℃, preferably in the temperature range of 170～230 ℃, more preferably in 170 The spinning is carried out in the temperature range of ~190°C, that is, the spinning temperature can be as described above. At such a spinning temperature, conventional melt spinning methods can be used to obtain nylon fibers for general textile use.

While in the prior art, the spinning temperature is generally in the range of 260-280° C., in comparison, the present invention can significantly reduce the spinning temperature of nylon fibers. Although there is no existing applicable theory to explain it, the inventor believes that the possible mechanism is as follows: the compound of the second main group metal can improve the strength of the nylon melt, improve the viscosity of the melt, reduce the melt index MFR, Therefore, it can withstand a large tensile force, even when the melt becomes a semi-melt after spinning, it still has good strength, so it can withstand a large tensile force, so that the fiber filaments can be melt-spun In the process, it can withstand the force encountered in the thinning step without breaking, thereby improving the spinnability of nylon fibers; in addition, the compound of the second main group metal can reduce the melting point of nylon, so it can be processed at a lower temperature spinning; another reason is that when the temperature is higher than the melting point of nylon, nylon melt will crystallize nylon due to overaging, and the precipitation temperature is significantly lower than the melting point of nylon, so the temperature of nylon spinning will be further reduced; due to the above factors The combined effects of the nylon fiber can be produced by spinning at the low temperature described in the present invention. But the effect of the present invention is not bound by this theory.

Beneficial effects: using the method of the present invention, nylon, especially nylon 6, can be spun to obtain nylon fibers that meet specifications for textile use, for example, the fineness can reach several deniers, or even finer. The spinning temperature adopting the method of the present invention is significantly lower than that of the prior art, so the energy consumption can be significantly reduced, and the cost can be reduced, and the spinning equipment, especially the spinneret or spinneret, no longer needs to use high pressure The equipment is heated, so the safety of industrial production is further improved.

Detailed ways

The present invention is further described below through specific examples. The features and advantages of the present invention will become clearer along with these descriptions. However, these examples are merely exemplary for explaining the present invention, but do not limit the scope of the present invention in any way. Those skilled in the art should understand that without departing from the spirit and scope of the present invention, the present invention can be modified and/or changed and/or equivalently replaced in terms of details, and these modifications/modifications/replacements should all fall within the scope of the present invention within the scope of the claimed protection.

The "parts" mentioned in the examples are all "parts by weight".

raw materials used

Nylon 6 slices: high-speed spinning pure nylon 6 slices produced by Ningbo Hengrun Company

Example 1

Heat and melt 7 parts of MgCl ₂ and 100 parts of nylon 6 slices, and the molten body is extruded by a screw extruder and sent to the spinning machine. The spinneret holes flow out the melt in the form of filaments, which are oiled and wound to obtain coiled filaments. The temperatures of the melt in each zone of the screw extruder are 225°C, 245°C, 245°C, and 250°C respectively. The temperature is 190° C., the spinneret hole diameter used is 0.35 mm, the length is 0.7 mm, and the winding speed is 1000 m/min. The fineness of the obtained winding yarn was 8 deniers, and the thermal drawing was performed 3.7 times at a temperature of 120° C. to obtain nylon 6 fibers with a fineness of 3 deniers. Its strength is 3.8cN/dtex and its elongation at break is 35%.

Example 2

Prepare the _CaCl2 additive masterbatch using the twin-screw extruder according to the ratio in Table 1, where the temperature of each zone of the extruder is: 250°C for zone I; 295°C for zone II; 280°C for zone III; 280°C for zone IV ℃.

Table 1: Additive masterbatch formulations containing _CaCl2 ingredients parts by mass Nylon 6 slices 80 Metal salt CaCl ₂ 20 Antioxidant (Antioxidant CA/Antioxidant 163) 1

The obtained CaCl ₂ additive masterbatch and nylon 6 slices were dried in a vacuum oven to remove moisture and small molecular substances. The drying temperature is between 90-100°C, and the drying time is 24-48 hours.

Then mix the _CaCl2 additive masterbatch and nylon 6 slices at a weight ratio of 5:1000 for heating and melting. The melt is extruded by a screw extruder and then sent to the spinning machine. The melt is quantitatively pressed into the spinning machine by a metering pump. Silk parts, the melt flows out in a thin filament state through the spinneret hole on the spinneret, and the coiled silk is wound with oil, and the temperature of the melt in each zone of the screw extruder is 220°C and 240°C respectively , 240°C, 245°C, the spinning temperature is 180°C, the hole diameter of the spinneret used is 0.3mm, the length is 0.7mm, and the winding speed is 1000m/min. The fineness of the obtained winding yarn was 10 deniers, and the thermal drawing was performed 3.3 times at a temperature of 120° C. to obtain nylon 6 fibers with a fineness of 3 deniers. It has a strength of 3.9 cN/dtex and an elongation at break of 35%.

Example 3

Prepare the Sr(Ac) ₂ additive masterbatch using the twin-screw extruder according to the ratio in Table 2, wherein the temperature of each zone of the extruder is: 260°C for zone I; 295°C for zone II; 290°C for zone III; 290°C for zone IV; Zone is 290°C.

Table 2: Additive Masterbatch Formula Containing Sr(Ac) ₂ ingredients parts by mass Nylon 6 slices 80 Metal salt Sr(Ac) ₂ 40

The obtained Sr(Ac) ₂ additive masterbatch and nylon 6 slices were dried in a vacuum oven to remove moisture and small molecular substances. The drying temperature is between 90-100°C, and the drying time is 24-48 hours.

Then the additive masterbatch of Sr(Ac) ₂ and nylon 6 slices are mixed, heated and melted at a weight ratio of 1:100, and the melt is extruded by a screw extruder and sent to the spinning machine, and the melt is quantitatively compressed by a metering pump. Into the spinning part, the melt flows out in the form of filaments through the spinneret holes on the spinneret, and is wound with oil to obtain coiled filaments. The temperature of the melt in each zone of the screw extruder is 230 ° C, 240°C, 240°C, 245°C, the spinning temperature is 190°C, the hole diameter of the spinneret used is 0.3mm, the length is 0.7mm, and the winding speed is 1000m/min. The fineness of the obtained wound yarn was 3 deniers, and it was thermally drawn 1.2 times at a temperature of 100° C. to obtain nylon 6 fibers with a fineness of 2.5 deniers. Its strength was 4.0 cN/dtex and its elongation at break was 38%.

Example 4

Nylon 6 fiber is produced according to the method of Example 3, the difference is that 80 parts of calcium phosphate is used instead of 40 parts of Sr(Ac) ₂ , the additive masterbatch and nylon 6 chips are mixed in a weight ratio of 28:1000, and the spinning temperature is 200°C . Nylon 6 fibers with a fineness of 3 denier were obtained.

Comparative Example 1

Heat and melt 100 parts of nylon 6 slices, and the molten body is extruded by a screw extruder to the spinning machine, and the melted body is quantitatively pressed into the spinning part by a metering pump, and the melted body is sprayed through the spinneret hole on the spinneret plate. It flows out in the form of filaments, and is oiled and wound to obtain coiled filaments. The temperatures of the melt in each zone of the screw extruder are 260°C, 305°C, 290°C, and 290°C, and the spinning temperature is 270°C. The hole diameter of the spinneret is 0.35mm, the length is 0.7mm, and the winding speed is 1000m/min. The fineness of the obtained winding yarn was 8 deniers, and the thermal drawing was performed 3.7 times at a temperature of 120° C. to obtain nylon 6 fibers with a fineness of 3 deniers. Its strength is 3.6cN/dtex and its elongation at break is 30%.

Comparative Example 2

Nylon 6 slices are spun by the method of comparative example 1, and its difference is: spinning temperature is 295 ℃, and winding speed is 900 m/min, and spinneret hole number is 48, and aperture is 0.3 millimeter, long diameter The ratio is 3:1. Obtaining the nylon 6 nylon winding yarn with a monofilament fineness of 7 deniers, carrying out 3.5 times thermal drafting to the obtained nylon 6 winding filaments, the temperature of the rollers is 90 degrees, and the temperature of the hot plate is 160 degrees, and the obtained monofilament fineness is 2.0 deniers of nylon fibers.

By comparing Examples 1-4 and Comparative Examples 1 and 2, it can be seen that when adding a compound of the second main group metal to nylon, nylon fibers with good quality can be spun out at a lower temperature, such as Embodiment 1-4 described, and existing method then needs to carry out spinning at very high temperature. Compared with Comparative Examples 1 and 2, Embodiments 1-4 save 10-20% energy consumption respectively.

Claims (18)

1, a kind of method of producing nylon fibre under low temperature, this method is a melt spinning method, it is characterized in that the gained molten mass carries out spinning under 160～250 ℃ low temperature then at the compound that adds a kind of second main group metal before the nylon fusion or during the fusion.

2, method according to claim 1 is characterized in that, carries out low-temp spinning when described temperature is 170～230 ℃.

3, method according to claim 1 and 2 is characterized in that, carries out low-temp spinning when described temperature is 170～190 ℃.

4, method according to claim 1 is characterized in that, described nylon is nylon 6.

5, method according to claim 1 is characterized in that, the compound of described second main group metal is second main group metal salt or the complex compound,

Wherein, the described second main group metal element is magnesium, calcium and strontium; The anion of described slaine or the part of complex compound are that phosphate radical, carbonate, carboxylate radical, nitrate radical, sulfate radical, sulfonate radical, inferior sulfate radical, halide anion, pseudohalogen ion and other are nitrogenous and/or contain oxygen and/or sulfur-bearing organic ligand or polynary part.

6, method according to claim 1 or 5 is characterized in that based on the weight meter of used nylon, the weight of the second main group metal element is 80ppm～10wt% in the compound of described second main group metal.

According to claim 1,5 or 6 described methods, it is characterized in that 7, based on the weight meter of used nylon, the weight of the second main group metal element is 0.01wt%～5wt% in the compound of described second main group metal.

According to claim 1,5,6 or 7 described methods, it is characterized in that 8, based on the weight meter of used nylon, the weight of the second main group metal element is 0.1wt%～5wt% in the compound of described second main group metal.

According to claim 1,5,6,7 or 8 described methods, it is characterized in that 9, based on the weight meter of used nylon, the weight of the second main group metal element is 0.5wt%～2wt% in the compound of described second main group metal.

According to claim 1, each described method of 5-9, it is characterized in that 10, the compound of described second main group metal and part nylon add after making the additive of the compound that comprises second main group metal again.

11, method according to claim 1 is characterized in that, the fusion that this method also is included in nylon adds auxiliary agent before or during the fusion, and described auxiliary agent is selected from one or more in antioxidant, ultra-violet absorber, light stabilizer and the antistatic additive.

12, according to claim 1 or 11 described methods, it is characterized in that, before the fusion of nylon or the antioxidant that adds during the fusion be in Hinered phenols, the phosphite one or more.

13, according to claim 1,11 or 12 described methods, it is characterized in that, the antioxidant that adds is: four [β-(3 ', 5 '-di-t-butyl-4 '-hydroxy phenyl) propionic acid] pentaerythritol ester, 1,1, in 3-three (2-methyl-4-hydroxyl-5-t-butyl-phenyl) butane, tricresyl phosphite (2, the 4-di-tert-butyl-phenyl) ester, three (3, the 5-di-tert-butyl-4-hydroxyl benzyl) isocyanates, the two lauryls of thio-2 acid, the trisnonyl phenyl phosphite one or more;

With used nylon weight, the addition of antioxidant is 0.001wt%-1wt%.

14, according to claim 1 or 11 described methods, it is characterized in that, described before the fusion of nylon or the ultra-violet absorber that adds during the fusion be benzotriazole, the organic aromatic substance of benzophenone class.

15, according to claim 1,11 or 14 described methods, it is characterized in that, described before the fusion of nylon or the ultra-violet absorber that adds during the fusion be: 2-(2-hydroxy-5-methyl base phenyl)-benzotriazole, 2-(2-hydroxyl-3, the 5-di-tert-butyl-phenyl)-benzotriazole, 2-(2-hydroxyl-5-octyl phenyl)-benzotriazole, Octabenzone, 2-(2-hydroxyl-3,5-di-tert-butyl-phenyl)-5-chlorinated benzotriazole, 2-(the 2-hydroxyl-3-tert-butyl group-5-aminomethyl phenyl)-5-chlorinated benzotriazole, carbon black, zinc oxide, in the titanium dioxide one or more;

In the weight of used nylon, the addition of ultra-violet absorber is 0.001wt%-1wt%.

According to claim 1 or 11 described methods, it is characterized in that 16, described light stabilizer is one or more in copper halide, hindered amines, phenols, benzophenone series, the triazole system;

In the weight of used nylon, the addition of described light stabilizer is 0.001wt%-1wt%.

17, according to claim 1 or 11 described methods, it is characterized in that described antistatic additive is one or more in fatty alcohol phosphate, fatty alcohol oxyalkylene ether phosphide salt, fatty alcohol phosphate potassium, lauryl sodium sulfate salt, stearic acid monoglyceride, laruyl alcohol oxygen vinethene phosphate kalium salt, the polyethylene glycol;

In the weight of used nylon, the addition of described antistatic additive is 0.001wt%-1wt%.

18, according to claim 1, each described method of 11-17, it is characterized in that, add again after the compound of the described auxiliary agent and second main group metal and part nylon are made additive.