A biobased polyamide carpet filament and a method of making the same

Abstract

The application belongs to the technical field of polyamide products, and discloses a bio-based polyamide carpet yarn, which comprises the following components in parts by weight: 5-20 parts of bio-based polyamide 56, 70-85 parts of polyamide 6, 10-15 parts of bio-based polyamide 56 / polyamide 6 copolymer and an additive, wherein the additive is selected from one or more of antioxidants, toning agents or matting agents, the antioxidants are 0.5-1.5 parts, the toning agents are 0.5-1 part, and the matting agents are 2-5 parts. The bio-based PA56 is used in combination with the conventional polyamide 6 to produce the carpet yarn, the obtained polyamide carpet yarn has good performance indexes, the price fluctuation problem caused by the fact that the bio-based PA56 is used to manufacture the carpet yarn is avoided, and the strength and dyeing performance of the polymer material after processing are improved.

Description

Technical Field

[0001] This invention belongs to the field of polyamide product technology, and relates to a bio-based polyamide carpet yarn and its preparation method. Background Technology

[0002] Polyamide (PA), commonly known as nylon, is a general term for polymers whose main molecular chain repeating units contain amide groups. It possesses excellent comprehensive properties, with a specific strength higher than metals. It also exhibits good mechanical properties, heat resistance, wear resistance, chemical resistance, flame retardancy, and self-lubricating properties. Furthermore, it is easy to process, has a low friction factor, and is suitable for reinforcement and modification with glass fiber and other materials. It is widely used in electronics, automotive parts, office supplies, and household goods. Traditional polyamide production processes use petroleum as raw material, through diacid / diamine monomer condensation and amino acid condensation / lactam monomer ring-opening polymerization. However, with the depletion of fossil fuels and the strengthening of sustainable development concepts, the development and application of biomass environmentally friendly raw materials have become a current research hotspot.

[0003] Bio-based polypentanediamine adipamide (PA56) is synthesized by condensing 1,5-pentanediamine with adipic acid instead of hexamethylenediamine. It possesses excellent bulkiness, abrasion resistance, resilience, and flame retardancy, making it an ideal raw material for high-end commercial and residential carpets. Bio-based polyamide 56 has a low monomer content and is less prone to gelation at high temperatures, allowing for the production of various polyamide 56 fibers using melt spinning. However, the demand for bio-based PA56 in various polyamide products, including civilian filaments, industrial yarns, staple fibers, and monofilaments, makes carpet yarn produced using pure bio-based PA56 susceptible to price fluctuations due to the supply and demand of bio-based raw materials, making production costs difficult to control. Therefore, developing a combination of bio-based PA56 and traditional polyamide 6 and polyamide 66 for carpet yarn production to stabilize product prices is an urgent problem to be solved. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a bio-based polyamide carpet yarn and its preparation method. The method uses a combination of bio-based PA56 and traditional polyamide 6 to produce carpet yarn, resulting in polyamide carpet yarn with excellent performance indicators. This avoids the price fluctuation problem caused by using only bio-based PA56 to manufacture carpet yarn, while also improving the strength, dyeing properties, and other properties of the polymer material after processing.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a bio-based polyamide carpet yarn comprising the following components in parts by weight: 5-20 parts of bio-based polyamide 56, 70-85 parts of polyamide 6, 10-15 parts of bio-based polyamide 56 / polyamide 6 copolymer and additives, wherein the additives are selected from one or more of antioxidants, colorants, or matting agents, wherein the antioxidant is 0.5-1.5 parts, the colorant is 0.5-1 parts, and the matting agent is 2-5 parts.

[0006] In this invention, bio-based polyamide 56 is prepared by condensation of 1,5-pentanediamine and adipic acid through bio-fermentation, with the bio-based content accounting for 35-45% of the bio-based polyamide 56. The relative viscosity of the bio-based polyamide 56 chips is 2.0-3.6, the terminal amino content is 30-65 mmol / kg, and the water content is 350-450 ppm.

[0007] The specific preparation method of the above-mentioned bio-based polyamide 56 / polyamide 6 copolymer in the technical solution of the present invention is as follows: Bio-based polyamide 56 salt and caprolactam are added to a reaction vessel, the mass ratio of bio-based polyamide 56 salt to caprolactam is 1:10-20, the stirring rate is 80-150 r / min, the air in the reaction vessel is first replaced with nitrogen gas at a flow rate of 60-120 ml / min and then heating is started. When the temperature reaches 165℃, the reaction is carried out for 3 hours, and then the temperature is programmed to rise to 170℃ for 1 hour, 175℃ for 15 minutes, 200℃ for 30 minutes, 230℃ for 15 minutes, and finally the temperature is raised to 270℃ for 1 hour. The crystallization temperature is controlled at 100-220℃ to obtain bio-based polyamide 56 / polyamide 6 copolymer particles.

[0008] The preparation method of the above-mentioned bio-based polyamide 56 salt in the technical solution of the present invention is as follows: Adipic acid is added to anhydrous ethanol at a mass ratio of 1:2.5-3.5, the heating temperature is set to 65°C, after the adipic acid dissolves, bio-based pentanediamine is added dropwise, the molar ratio of bio-based pentanediamine to adipic acid is 1:1, so that adipic acid and pentanediamine react fully. After reacting for 6-8 minutes, white crystals precipitate. After reacting for 1 hour, the mixture is filtered and dried to obtain bio-based polyamide 56 salt.

[0009] In this invention, the antioxidant is selected from N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate n-octadecyl alcohol ester, tris[2,4-di-tert-butylphenyl]phosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, 2,2-methylene-bis(4-ethyl-6-tert-butylphenol), 4,4-methoxy-bis(4-ethyl-6-tert-butylphenol), etc. Butylene-bis-(6-tert-butyl-m-cresol), 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene; the colorant is a red, yellow, blue, or black polyamide 6-color masterbatch carrier; the matting agent is selected from titanium dioxide, with a purity of 99.0-99.9%, anatase type, and a particle size of 150-300 nanometers.

[0010] The specific preparation method of the red, yellow, blue, or black polyamide 6-color masterbatch in the technical solution of this invention is as follows: Red primary colorant, blue primary colorant, yellow primary colorant, and black primary colorant are mixed with polyamide 6 matrix and melt-extruded in a twin-screw extruder to obtain the red, yellow, blue, or black polyamide 6-color masterbatch; the mass ratio of red primary colorant to polyamide 6 matrix is ​​1:(65-70), the mass ratio of blue primary colorant to polyamide 6 matrix is ​​1:(55-68), the mass ratio of yellow primary colorant to polyamide 6 matrix is ​​1:(55-60), and the mass ratio of black primary colorant to polyamide 6 matrix is ​​1:(75-80). Other colors can also be adjusted using the red, yellow, blue, or black polyamide 6-color masterbatch according to customer needs.

[0011] Secondly, the present invention provides a method for preparing bio-based polyamide carpet fibers, comprising the following steps: A1. The dried bio-based polyamide 56, polyamide 6, bio-based polyamide 56 / polyamide 6 copolymer and additives are added to the hopper and then melt-extruded in the screw through a screw extruder; A2. The extruded melt is pressurized by a pressure pump and then enters a metering pump. After being filtered by the spinning assembly, it is ejected from the spinneret. A3. The ejected molten filaments are cooled by blowing, oiled, and wound to obtain the bio-based polyamide carpet yarn.

[0012] The screw extruder described in step A1 of the technical solution of the present invention includes 5 heating zones. The heating temperature of the first to fifth zones is 250 to 300°C, and the screw rotation speed is 50 to 100 r / min.

[0013] The screw extruder described in step A1 of the technical solution of the present invention includes 5 heating zones, and the specific temperatures of the 5 heating zones are as follows: Zone 1 temperature: 250~280℃, Zone 2 temperature: 250~280℃, Zone 3 temperature: 270~300℃, Zone 4 temperature: 280~300℃, Zone 5 temperature: 280~300℃.

[0014] In step A3 of the technical solution of the present invention, the air blowing cooling adopts the side blowing cooling method, and the winding speed is 3000-4500m / min.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention uses a combination of bio-based PA56 and traditional PA6 to produce carpet yarn. The resulting polyamide carpet yarn has excellent performance indicators and avoids the price fluctuation problem caused by using only bio-based PA56 to manufacture carpet yarn.

[0016] In this invention, the addition of bio-based PA56 to the bio-based PA56 / 6 copolymer disrupts the regularity of the PA6 chain, reduces the number of hydrogen bonds in the copolymer, and forms cavities inside the polymer, thereby increasing the mobility of the chain segments and effectively improving the melt flowability of PA6, allowing PA6 to achieve better flowability at the same temperature. At the same time, by controlling the content of PA56, the terminal amine and terminal carboxyl groups of PA56 / 6 are in a relatively balanced state, which can improve the strength, dyeing and other properties of the polymer material after processing. Detailed Implementation

[0017] The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of protection of the present invention. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art. Unless otherwise specified, the test methods in the following embodiments are conventional methods.

[0018] The following examples use bio-based polyamide 56 with a bio-based content of 40% and a relative viscosity of 2.78, a terminal amino content of 45 mmol / kg, a water content of 400 ppm, and a melting point of 254°C.

[0019] Example 1 14.6 kg of adipic acid was added to 36.5 kg of anhydrous ethanol, and the heating temperature was set to 65 °C. After the adipic acid dissolved, 10.2 kg of bio-based pentanediamine was added dropwise to allow the adipic acid and pentanediamine to react fully. After 8 min of reaction, white crystals precipitated. After 1 h of reaction, the mixture was filtered and dried to obtain bio-based polyamide 56 salt.

[0020] Example 2 20 kg of bio-based polyamide 56 salt and 300 kg of caprolactam were added to a reactor. The stirring rate was 90 r / min. The air in the reactor was first replaced with nitrogen gas at a flow rate of 70 ml / min before heating was started. When the temperature reached 165℃, the reaction was carried out for 3 hours. Then the temperature was programmed to rise to 170℃ for 1 hour, 175℃ for 15 minutes, 200℃ for 30 minutes, and 230℃ for 15 minutes. Finally, the temperature was raised to 270℃ for 1 hour. The condensate temperature was 10℃, and the crystallization temperature was controlled at 152℃ to obtain bio-based polyamide 56 / polyamide 6 copolymer particles.

[0021] Comparative Example 1 20 kg of bio-based polyamide 56 salt and 300 kg of caprolactam were added to a reactor. The stirring rate was 90 r / min. After replacing the air in the reactor with nitrogen gas at a flow rate of 70 ml / min, the reactor was heated to 270℃ and reacted for 6 h. The condensate temperature was 10℃ and the crystallization temperature was controlled at 152℃ to obtain bio-based polyamide 56 / polyamide 6 copolymer particles.

[0022] Comparative Example 2 20 kg of polyamide 56 salt and 300 kg of caprolactam were added to a reactor. The stirring rate was 90 r / min. The air in the reactor was first replaced with nitrogen at a flow rate of 70 ml / min before heating was started. When the temperature reached 165℃, the reaction was carried out for 3 hours. Then the temperature was programmed to rise to 170℃ for 1 hour, 175℃ for 15 minutes, 200℃ for 30 minutes, and 230℃ for 15 minutes. Finally, the temperature was raised to 270℃ for 1 hour. The condensate temperature was 10℃, and the crystallization temperature was controlled at 152℃ to obtain polyamide 56 / 6 copolymer particles.

[0023] The performance indicators of the polyamide copolymers obtained in Example 2 and Comparative Examples 1-2 are shown in Table 1.

[0024] Table 1 Performance indicators of different polyamide copolymers As can be seen from Table 1, the performance of the bio-based polyamide 56 / polyamide 6 copolymer is comparable to that of the conventional polyamide 56 / 6 copolymer. However, compared with the bio-based polyamide 56 / polyamide 6 copolymer obtained by conventional heating reaction, the performance of the bio-based polyamide 56 / polyamide 6 copolymer obtained by the staged reaction in this invention is improved.

[0025] Example 3 The production of bio-based polyamide carpet yarn using melt extrusion specifically includes the following steps: (1) 5 kg of dried bio-based polyamide 56, 85 kg of polyamide 6, 10 kg of bio-based polyamide 56 / polyamide 6 copolymer, 0.5 kg of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine, 0.5 kg of red polyamide 6 color carrier, and 2 kg of titanium dioxide were added to the hopper and then melt-extruded in the screw through a screw extruder. The screw extruder includes 5 heating zones with temperatures of 255℃, 268℃, 275℃, 282℃, and 285℃ respectively. The screw speed is 80 r / min.

[0026] (2) The extruded melt is pressurized by a pressure pump and then enters a metering pump. After being filtered by the spinning assembly, it is ejected from the spinneret. (3) The ejected molten filaments are cooled by blowing, oiled and wound to obtain bio-based polyamide carpet yarn. The blowing cooling is done by side blowing and the winding speed is 4000m / min.

[0027] Example 4 The production of bio-based polyamide carpet yarn using melt extrusion specifically includes the following steps: (1) 15 kg of dried bio-based polyamide 56, 80 kg of polyamide 6, 13 kg of bio-based polyamide 56 / polyamide 6 copolymer, 1 kg of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine, 0.8 kg of red polyamide 6 color masterbatch, and 3 kg of titanium dioxide were added to the hopper and then melt-extruded in the screw through a screw extruder. The screw extruder includes 5 heating zones with temperatures of 255℃, 268℃, 275℃, 282℃, and 285℃ respectively. The screw speed is 100 r / min.

[0028] (2) The extruded melt is pressurized by a pressure pump and then enters a metering pump. After being filtered by the spinning assembly, it is ejected from the spinneret. (3) The ejected molten filaments are cooled by blowing, oiled and wound to obtain bio-based polyamide carpet yarn. The blowing cooling is done by side blowing and the winding speed is 4500m / min.

[0029] Comparative Example 3 The production of bio-based polyamide carpet yarn using melt extrusion specifically includes the following steps: (1) Add 5 kg of dried bio-based polyamide 56, 85 kg of polyamide 6, 10 kg of polyamide 56 / 6 copolymer, 0.5 kg of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine, 0.5 kg of red polyamide 6 color masterbatch, and 2 kg of titanium dioxide into the hopper, and then melt-extrude them in the screw extruder. The screw extruder includes 5 heating zones with temperatures of 255℃, 268℃, 275℃, 282℃, and 285℃ respectively. The screw speed is 80 r / min.

[0030] (2) The extruded melt is pressurized by a pressure pump and then enters a metering pump. After being filtered by the spinning assembly, it is ejected from the spinneret. (3) The ejected molten filaments are cooled by blowing, oiled and wound to obtain bio-based polyamide carpet yarn. The blowing cooling is done by side blowing and the winding speed is 4000m / min.

[0031] Comparative Example 4 The production of polyamide carpet yarn using melt extrusion specifically includes the following steps: (1) Add 5 kg of dried polyamide 56, 85 kg of polyamide 6, 10 kg of polyamide 56 / 6 copolymer, 0.5 kg of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine, 0.5 kg of red polyamide 6 color masterbatch, and 2 kg of titanium dioxide into the hopper, and then melt-extrude them in the screw through a screw extruder. The screw extruder includes 5 heating zones with temperatures of 255℃, 268℃, 275℃, 282℃, and 285℃ respectively. The screw speed is 80 r / min.

[0032] (2) The extruded melt is pressurized by a pressure pump and then enters a metering pump. After being filtered by the spinning assembly, it is ejected from the spinneret. (3) The ejected molten filaments are cooled by blowing, oiled and wound to obtain bio-based polyamide carpet yarn. The blowing cooling is done by side blowing and the winding speed is 4000m / min.

[0033] Comparative Example 5 The production of polyamide carpet yarn using melt extrusion specifically includes the following steps: (1) 10 kg of dried bio-based polyamide 56, 90 kg of polyamide 6, 0.5 kg of N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine, 0.5 kg of red polyamide 6 color masterbatch, and 2 kg of titanium dioxide were added to the hopper and then melt-extruded in the screw through a screw extruder. The screw extruder includes 5 heating zones with temperatures of 255℃, 268℃, 275℃, 282℃, and 285℃ respectively. The screw speed is 80 r / min.

[0034] (2) The extruded melt is pressurized by a pressure pump and then enters a metering pump. After being filtered by the spinning assembly, it is ejected from the spinneret. (3) The ejected molten filaments are cooled by blowing, oiled and wound to obtain bio-based polyamide carpet yarn. The blowing cooling is done by side blowing and the winding speed is 4000m / min.

[0035] The performance indicators of the polyamide carpet yarns obtained in Examples 3-4 and Comparative Examples 3-4 are shown in Table 2.

[0036] Table 2 Performance indicators of polyamide carpet fibers obtained from different components Linear density specifications (dtex / f) 235 / 36 235 / 36 235 / 36 235 / 36 235 / 36 Fracture strength (MPa) 7.39 7.25 7.32 7.68 7.75 Elongation at break (%) 17.8 16.9 17.1 19.4 20.1 Dry heat shrinkage rate (180℃*2min%) 4.3 4.1 4.2 4.6 4.7 Boiling water shrinkage rate (%) 6.8 6.4 6.5 7.4 7.5 Initial modulus (cN / dtex) 35.6 34.7 34.9 38.5 39.8 As can be seen from Table 2, the performance of bio-based polyamide carpet yarn obtained by adding bio-based polyamide 56 is better than that of conventional polyamide carpet yarn. This is because the addition of bio-based PA56 to the bio-based PA56 / 6 copolymer disrupts the regularity of the PA6 chain, reduces the number of hydrogen bonds in the copolymer, forms cavities inside the polymer, and thus increases the mobility of the chain segments, effectively improving the melt flowability of PA6. This allows PA6 to obtain better flowability at the same temperature, thereby improving the processing performance of the carpet yarn.

[0037] The embodiments described above are merely preferred embodiments of the present invention and are only used to explain the present invention. They are not intended to limit the scope of the present invention. For those skilled in the art, other implementation methods can be easily made by substitution or modification based on the technical content disclosed in this specification. Therefore, all changes and improvements made on the principle of the present invention should be included within the scope of the patent application of the present invention.

Claims

1. A bio-based polyamide carpet yarn, characterized in that, The composition comprises the following components in parts by weight: 5-20 parts of bio-based polyamide 56, 70-85 parts of polyamide 6, 10-15 parts of bio-based polyamide 56 / polyamide 6 copolymer, and additives. The additives are selected from one or more of antioxidants, colorants, or matting agents. The antioxidant is 0.5-1.5 parts, the colorant is 0.5-1 part, and the matting agent is 2-5 parts. The preparation method of the bio-based polyamide 56 / polyamide 6 copolymer is as follows: Bio-based polyamide 56 salt and caprolactam are added to a reaction vessel. The mass ratio of bio-based polyamide 56 salt to caprolactam is 1:10-20. The stirring rate is 80-150 r / min. The air in the reaction vessel is first replaced with nitrogen gas at a flow rate of 60-120 ml / min, and then heating begins. When the temperature reaches 165 ℃, the reaction is carried out for 3 hours. Then, the temperature is programmed to rise to 170 ℃ for 1 hour, 175 ℃ for 15 minutes, and 200 ℃ for 20 minutes. The reaction was carried out at ℃ for 30 min, at 230 ℃ for 15 min, and finally at 270 ℃ for 1 h. The crystallization temperature was controlled at 100~220 ℃ to obtain bio-based polyamide 56 / polyamide 6 copolymer particles.

2. The bio-based polyamide carpet yarn according to claim 1, characterized in that, The bio-based polyamide 56 chips have a relative viscosity of 2.0~3.6, a terminal amino content of 30~65 mmol / kg, and a water content of 350~450 ppm.

3. The bio-based polyamide carpet yarn according to claim 1, characterized in that, The preparation method of the bio-based polyamide 56 salt is as follows: Adipic acid is added to anhydrous ethanol at a mass ratio of 1:2.5~3.

5. The heating temperature is set to 65 ℃. After the adipic acid dissolves, bio-based pentanediamine is added dropwise. The molar ratio of bio-based pentanediamine to adipic acid is 1:

1. The adipic acid and pentanediamine react fully. After reacting for 6~8 min, white crystals precipitate. After reacting for 1 h, the mixture is filtered and dried to obtain the bio-based polyamide 56 salt.

4. The bio-based polyamide carpet yarn according to claim 1, characterized in that, The antioxidant is selected from N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate n-octadecyl alcohol ester, tris[2,4-di-tert-butylphenyl]phosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, 2,2-methylene-bis(4-ethyl-6-tert-butylphenol), 4,4-metanoyl-bis-(6-tert-butyl-m-cresol), 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, and 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene; the colorant is a red, yellow, blue, or black polyamide 6 masterbatch carrier; and the matting agent is selected from titanium dioxide.

5. The bio-based polyamide carpet yarn according to claim 4, characterized in that, The preparation method of the colorant is as follows: red primary colorant, blue primary colorant, yellow primary colorant, and black primary colorant are mixed with polyamide 6 matrix and melt-extruded in a twin-screw extruder to obtain red, yellow, blue, or black polyamide 6 color masterbatch; the mass ratio of red primary colorant to polyamide 6 matrix is ​​1:(65-70), the mass ratio of blue primary colorant to polyamide 6 matrix is ​​1:(55-68), the mass ratio of yellow primary colorant to polyamide 6 matrix is ​​1:(55-60), and the mass ratio of black primary colorant to polyamide 6 matrix is ​​1:(75-80).

6. A method for preparing a bio-based polyamide carpet yarn according to any one of claims 1 to 5, characterized in that, Includes the following steps: A1. The dried bio-based polyamide 56, polyamide 6, bio-based polyamide 56 / polyamide 6 copolymer and additives are added to the hopper and then melt-extruded in the screw through a screw extruder; A2. The extruded melt is pressurized by a pressure pump and then enters a metering pump. After being filtered by the spinning assembly, it is ejected from the spinneret. A3. The ejected molten filaments are cooled by blowing, oiled, and wound to obtain the bio-based polyamide carpet yarn.

7. The method for preparing bio-based polyamide carpet yarn according to claim 6, characterized in that, The screw extruder described in step A1 includes 5 heating zones. The heating temperature of the first to fifth zones is 250~300 ℃, and the screw speed is 50~100 r / min.

8. The method for preparing bio-based polyamide carpet yarn according to claim 6, characterized in that, The screw extruder described in step A1 includes 5 heating zones, and the specific temperatures of the 5 heating zones are as follows: Zone 1 temperature: 250~280 ℃, Zone 2 temperature: 250~280 ℃, Zone 3 temperature: 270~300 ℃, Zone 4 temperature: 280~300 ℃, Zone 5 temperature: 280~300 ℃.

9. The method for preparing bio-based polyamide carpet yarn according to claim 6, characterized in that, The air cooling in step A3 is achieved by side blowing, with a winding speed of 3000~4500 m / min.

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