A process for the preparation of furan monomer modified polyamide industrial yarn

Abstract

This invention discloses a method for preparing furan-based monomer-modified polyamide industrial yarn, comprising the following steps: 1) First, prepare carboxyl-terminated PA6 oligomers for later use; 2) Mix the carboxyl-terminated PA6 oligomers obtained in step 1) with diamine and 2,5-furandimethylamine, add a catalyst after uniform mixing, and carry out polymerization reaction in a closed oxygen-free reaction system. After the reaction is completed, discharge and pelletize to obtain furan-based monomer-modified polyamide chips; 3) Extract and dry the furan-based monomer-modified polyamide chips obtained in step 2), then melt spin them, and after cooling, oiling, stretching, heat setting and winding, obtain furan-based monomer-modified polyamide industrial yarn with a strength >8.2 cN / dtex and an elongation at break in the range of 10-25%, which can be used in the field of polyamide industrial yarns such as automotive seat belts and tire cords.

Description

Technical Field

[0001] This invention relates to the field of polyamide fiber technology, and specifically to a method for preparing furan-based monomer-modified polyamide industrial yarn. Background Technology

[0002] Polyamide is a general term for polymers whose main chain repeating units contain amide groups. It has excellent comprehensive properties, such as good mechanical properties, wear resistance, heat resistance and easy processing. It is mainly used in the manufacture of engineering plastics and fibers, and has a wide range of applications in automotive lightweighting, machinery manufacturing, textiles and other fields.

[0003] Currently, the most common industrial yarns on the market are polyester and polyamide. However, polyester industrial yarns are not as good as polyamide industrial yarns in terms of abrasion resistance, hydrolysis resistance, and chemical resistance. Polyamide industrial yarns have limited strength and a limited variety of types. There is still a lack of development of high-strength, stable, and environmentally friendly industrial yarns.

[0004] Polyamide industrial yarns, used in fiber manufacturing, have considerable applications in conveyor belts, ropes, safety belts, tire cords, and industrial filter cloths due to their advantages such as high strength, low elongation, corrosion resistance, and aging resistance. However, currently, polyamide industrial yarns are mainly made of PA6 and PA66, and the industrial yarns made from these two materials have high moisture regain and limited strength, affecting their subsequent use.

[0005] With technological advancements and expanding application scenarios, modifying existing polymers to create high-performance, differentiated products has become a growing trend. However, both PA6 and PA66 are petroleum-based polymers, leading to issues such as over-reliance on fossil resources and environmental pollution. Furan-based monomers, on the other hand, are gaining attention due to their green, environmentally friendly, and renewable properties, as well as the fact that their ring structure is similar to benzene rings, making them suitable for developing high-performance polyamide products.

[0006] In order to continuously meet people's demand for high-performance bio-based polyamides and their industrial filaments, the present invention is of great significance for the development of furan-based monomer-modified polyamides and their industrial filaments. Summary of the Invention

[0007] In view of the problems existing in the prior art, the purpose of the present invention is to provide a method for preparing furan-based monomer-modified polyamide industrial yarn. The polyamide industrial yarn prepared by the method of the present invention has high strength and stable performance.

[0008] The technical solution of the present invention is as follows:

[0009] A method for preparing furanyl monomer-modified polyamide industrial yarn, characterized by comprising the following steps:

[0010] 1) First, prepare carboxyl-terminated PA6 oligomers for later use;

[0011] 2) Mix the carboxyl-terminated PA6 oligomer obtained in step 1) with diamine and 2,5-furandimethylamine. After mixing evenly, add catalyst and carry out polymerization reaction in a closed oxygen-free reaction system. After the reaction is completed, discharge and pelletize to obtain furanyl monomer modified polyamide chips.

[0012] 3) The furanyl monomer-modified polyamide chips obtained in step 2) are extracted, dried, melt-spun, and then cooled, oiled, drawn, heat-set, and wound to obtain furanyl monomer-modified polyamide industrial yarn.

[0013] Furthermore, the specific process for preparing the carboxyl-terminated PA6 oligomer in step 1) is as follows:

[0014] Caprolactam, ultrapure water, and aliphatic dicarboxylic acid are placed in a closed, oxygen-free reaction system and reacted at 220-240℃ for 2-4 hours to obtain carboxyl-terminated PA6 oligomers.

[0015] Furthermore, the aliphatic dicarboxylic acid is one or more of succinic acid, adipic acid, and sebacic acid.

[0016] Furthermore, the mass ratio of caprolactam, ultrapure water, and aliphatic dicarboxylic acid is 1:0.04-0.1:0.1-0.5.

[0017] Furthermore, the specific process of step 2) is as follows:

[0018] The carboxyl-terminated PA6 oligomer, diamine, and 2,5-furandimethylamine were mixed and then a catalyst was added. The mixture was heated to 160-200℃ in a closed, oxygen-free reaction system for 1-2 hours. Then, the temperature was raised to 250-270℃ and the reaction was carried out under vacuum for 2-4 hours. After the reaction was completed, the material was discharged and granulated to obtain furanyl monomer-modified polyamide chips.

[0019] Furthermore, the diamine is a fatty chain diamine with a main chain comprising C5-C12; wherein the total molar ratio of the fatty chain diamine and 2,5-furan dimethylamine to the aliphatic diacid in step 1) is 1.02-1.1:1.

[0020] Furthermore, the diamine is one of pentanediamine, hexanediamine, or decanediamine.

[0021] Further, in step 2), the catalyst is one or more of boric acid, triphenyl phosphite, sodium hypophosphite, and sodium phosphite, and its addition amount accounts for 0.2-0.8% of the total weight of caprolactam, aliphatic chain diamine, and 2,5-furan dimethylamine.

[0022] Furthermore, in step 3), the furanyl monomer-modified polyamide chips, after extraction and vacuum drum drying, have a relative viscosity of 2.8-3.6 and a water content of <400ppm.

[0023] Further, in step 3), the spinning temperature is controlled at 280-300℃. The drawing process utilizes multiple hot rollers to gradually increase the temperature and speed. The temperature and speed of the drawing hot roller 1 are controlled at 40-60℃ and 600-900 m / min, respectively; the temperature and speed of the drawing hot roller 2 are controlled at 70-100℃ and 1000-1800 m / min, respectively; and the temperature and speed of the drawing hot roller 3 are controlled at 120-150℃ and 2000-3000 m / min, respectively. After the initial drawing, the process enters the heat setting process, where the temperature of the heat setting roller is controlled at 160-180℃ and the speed at 3050-3600 m / min. Finally, the winding process is completed, where the winding speed is controlled at 3000-3500 m / min. The drawing ratio in the above process is calculated based on the speed ratio of the fastest hot roller to the lowest roller, with the drawing ratio ranging from 5.0 to 6.0 times.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] 1) This invention utilizes 2,5-furan dimethylamine and aliphatic chain diamine to copolymerize and modify PA6, and then combines it with a spinning process to prepare modified polyamide industrial yarn;

[0026] 2) This invention uses a melt copolymerization modification method to introduce aliphatic chain diamine and bio-based furan ring rigid structure without disturbing the regularity of PA6 molecular chain. This reduces the number of amide bonds between molecules, improves the overall rigidity of the material, and improves the dimensional stability and mechanical properties of PA6. Combined with melt spinning process, the modified polyamide industrial yarn prepared in this way has the advantages of high strength, stable performance and green manufacturing.

[0027] 3) Using the method of the present invention, the final obtained furan-based monomer-modified polyamide industrial yarn has a strength >8.2 cN / dtex and an elongation at break in the range of 10-25%, and can be used in the field of polyamide industrial yarns such as automotive seat belts and tire cords. Detailed Implementation

[0028] The present invention will be further described below with reference to embodiments, but the scope of protection of the present invention is not limited to the scope described.

[0029] In this invention, unless otherwise specified, the raw materials and equipment used can be purchased from the market or are commonly used in the field. The methods in the embodiments, unless otherwise specified, are conventional methods in the field. Example 1

[0030] A method for preparing industrial filaments of polyamide modified with furanyl monomers includes the following steps:

[0031] 1) Preparation of carboxyl-terminated PA6 oligomers: 100 parts caprolactam, 4 parts ultrapure water and 10 parts adipic acid were placed in a closed oxygen-free reaction system and reacted at 240℃ for 4 h to obtain carboxyl-terminated PA6 oligomers.

[0032] 2) Preparation of furanyl monomer modified polyamide chips: 5.9 parts of pentanediamine, 1.8 parts of 2,5-furandimethylamine and the above carboxyl-terminated PA6 oligomer were mixed and 0.4 parts of boric acid were added. The mixture was heated to 190°C for 2 hours in a closed oxygen-free reaction system, then heated to 260°C and reacted under vacuum for 4 hours. The mixture was then discharged and granulated to obtain furanyl monomer modified polyamide chips.

[0033] 3) Preparation of modified polyamide industrial yarn: The above-mentioned furanyl monomer modified polyamide chips were extracted with hot pure water, dried in a vacuum drum, and then melt-spun at 280-300℃. After cooling and oiling, drawing, heat setting and winding, the temperature of the drawing hot rollers 1, 2 and 3 were 40, 70 and 140℃ respectively, the rotation speed of the hot rollers 1, 2 and 3 were 600, 1000 and 2500 m / min respectively, the temperature and rotation speed of the heat setting roller were 160℃ and 3300 m / min respectively, and the winding roller speed was 3250 m / min. Finally, the modified polyamide industrial yarn was obtained. Example 2

[0034] A method for preparing furanyl monomer-modified polyamide and its industrial filaments includes the following steps:

[0035] 1) Preparation of carboxyl-terminated PA6 oligomers: 100 parts caprolactam, 5 parts ultrapure water and 20 parts adipic acid were placed in a closed oxygen-free reaction system and reacted at 235℃ for 3h to obtain carboxyl-terminated PA6 oligomers.

[0036] 2) Preparation of furanyl monomer modified polyamide chips: 9 parts of pentanediamine, 7.5 parts of 2,5-furandimethylamine and the above carboxyl-terminated PA6 oligomer were mixed, and 0.4 parts of boric acid and 0.2 parts of triphenyl phosphite were added. The mixture was heated to 190℃ for 2 hours in a closed oxygen-free reaction system, then heated to 260℃ and reacted under vacuum for 4 hours. The mixture was then discharged and granulated to obtain furanyl monomer modified polyamide chips.

[0037] 3) Preparation of modified polyamide industrial yarn: The above-mentioned furanyl monomer modified polyamide chips were extracted with hot pure water, dried in a vacuum drum, melt-spun at 280-300℃, and then cooled, oiled, drawn, heat-set, and wound. The temperatures of the drawing hot rollers 1, 2, and 3 were 50, 80, and 140℃, respectively, and the rotation speeds of the hot rollers 1, 2, and 3 were 600, 1300, and 2800 m / min, respectively. The temperature and rotation speed of the heat-setting rollers were 170℃ and 3500 m / min, respectively, and the winding roller speed was 3300 m / min. Finally, modified polyamide industrial yarn was obtained. Example 3

[0038] A method for preparing furanyl monomer-modified polyamide and its industrial filaments includes the following steps:

[0039] 1) Preparation of carboxyl-terminated PA6 oligomers: 100 parts caprolactam, 6 parts ultrapure water and 40 parts adipic acid were placed in a closed oxygen-free reaction system and reacted at 230℃ for 3h to obtain carboxyl-terminated PA6 oligomers.

[0040] 2) Preparation of furanyl monomer modified polyamide chips: 17.5 parts hexamethylenediamine, 19 parts 2,5-furandimethylamine and the above carboxyl-terminated PA6 oligomer were mixed, and 0.5 parts boric acid and 0.3 parts triphenyl phosphite were added. The mixture was heated to 200℃ and reacted for 2 hours in a closed oxygen-free reaction system, then heated to 265℃ and reacted under vacuum for 4 hours. The product was then discharged and granulated to obtain furanyl monomer modified polyamide chips.

[0041] 3) Preparation of modified polyamide industrial yarn: The above-mentioned furanyl monomer modified polyamide chips are extracted with hot pure water, dried in a vacuum drum, melt-spun at 280-300℃, and then cooled, oiled, drawn, heat-set and wound. The temperatures of the drawing hot rollers 1, 2 and 3 are 60, 100 and 150℃ respectively, the rotation speeds of the hot rollers 1, 2 and 3 are 600, 1500 and 3000 m / min respectively, the temperature and rotation speed of the heat-setting rollers are 180℃ and 3600 m / min respectively, and the winding roller speed is 3500 m / min. Finally, modified polyamide industrial yarn is obtained. Comparative Example 1

[0042] PA6 chips with a conventional high gloss and relative viscosity of 2.8 available on the market were selected for melt spinning. The spinning temperature was controlled at 260-280℃. The PA6 industrial yarn was obtained by performing similar operations as in Example 1, including cooling and oiling, stretching, heat setting and winding. Comparative Example 2

[0043] The difference from Example 1 is that no furanyl monomer is added to the polymerization system; that is, 2,5-furandimethylamine is replaced by pentamethylenediamine, and the process includes the following steps:

[0044] 1) Preparation of carboxyl-terminated PA6 oligomers: 100 parts caprolactam, 4 parts ultrapure water and 10 parts adipic acid were placed in a closed oxygen-free reaction system and reacted at 240℃ for 4 h to obtain carboxyl-terminated PA6 oligomers.

[0045] 2) Preparation of modified polyamide chips: 7.3 parts of pentanediamine and the above carboxyl-terminated PA6 oligomer were mixed and 0.4 parts of boric acid were added. The mixture was heated to 190°C and reacted for 2 hours in a closed oxygen-free reaction system. Then the temperature was raised to 260°C and the reaction was carried out under vacuum for 4 hours. The mixture was then discharged and granulated to obtain modified polyamide chips.

[0046] 3) Preparation of modified polyamide industrial yarn: The modified polyamide chips were extracted with hot pure water, dried in a vacuum drum, melt-spun at 270-280℃, and then cooled, oiled, drawn, heat-set, and wound. The temperatures of the drawing rollers 1, 2, and 3 were 40, 70, and 140℃, respectively, and the rotation speeds of the rollers 1, 2, and 3 were 600, 1000, and 2500 m / min, respectively. The temperature and rotation speed of the heat-setting rollers were 160℃ and 3300 m / min, respectively, and the winding roller speed was 3250 m / min. Finally, modified polyamide industrial yarn was obtained. Comparative Example 3

[0047] PA66 chips with a conventional high gloss and relative viscosity of 2.8 available on the market were selected for melt spinning. The spinning temperature was controlled at 280-300℃. The PA66 industrial yarn was obtained by performing similar operations as in Example 3, including cooling and oiling, stretching, heat setting and winding.

[0048] Performance testing

[0049] The performance of the industrial filaments prepared in each embodiment and comparative example was tested, and the results are shown in the table below:

[0050] project Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Fracture strength (cN / dtex) 8.4 8.6 9.0 7.8 8.1 8.6 Elongation at break (%) 14 17 13 19 15 16

[0051] As can be seen from the table, compared with the PA6 industrial yarn of Comparative Example 1, the furanyl-modified polyamide industrial yarns prepared in each example all have higher breaking strength; at the same time, compared with the PA66 industrial yarn of Comparative Example 3, the modified polyamide industrial yarns prepared in each example can achieve the performance of PA66 industrial yarn; compared with Comparative Example 2 and Example 1, it was found that without the addition of 2,5-furandimethylamine to modify PA6, the modified polyamide industrial yarn prepared in this way has lower strength; this is because introducing furanyl groups and other aliphatic chain components into the PA6 molecular chain can improve the overall strength and dimensional stability of the material to a certain extent, thereby preparing industrial yarns with stable performance and high strength.

Claims

1. A process for the preparation of a furanyl monomer-modified polyamide industrial yarn, characterized in that The method comprises the following steps: 1) first, prepare carboxyl-terminated PA6 oligomer for use; the preparation process of the carboxyl-terminated PA6 oligomer is as follows: Caprolactam, ultrapure water and aliphatic diacid are placed in a closed oxygen-free reaction system, and reacted at 220-240℃ for 2-4h to obtain the carboxyl-terminated PA6 oligomer; the aliphatic diacid is one or more of succinic acid, adipic acid and sebacic acid, and the mass ratio of caprolactam, ultrapure water and aliphatic diacid is 1:0.04-0.1:0.1-0.5; 2) mix the carboxyl-terminated PA6 oligomer prepared in step 1) with diamine and 2,5-furandimethylamine, add a catalyst after uniform mixing, and perform polymerization reaction in a closed oxygen-free reaction system; after the reaction is completed, the product is discharged and cut into particles to obtain furan monomer modified polyamide chips; the specific process of step 2) is as follows: Mix the carboxyl-terminated PA6 oligomer with diamine and 2,5-furandimethylamine, add a catalyst after uniform mixing, and perform polymerization reaction in a closed oxygen-free reaction system; after the reaction is completed, the product is discharged and cut into particles to obtain furan monomer modified polyamide chips; the specific process of step 2) is as follows: The diamine is a fatty chain diamine containing C5-C12; the total molar amount of the fatty chain diamine and 2,5-furandimethylamine is 1.02-1.1 times the molar amount of the aliphatic diacid in step 1); 3) after extraction and drying, the furan monomer modified polyamide chips obtained in step 2) are subjected to melt spinning, cooling, oiling, drawing, heat setting and winding to obtain furan monomer modified polyamide industrial yarns.

2. A process for the preparation of a furanyl monomer-modified polyamide industrial yarn according to claim 1, characterized in that The diamine is one of pentanediamine, hexanediamine and decanediamine.

3. A process for the preparation of a furan-based monomer-modified polyamide industrial yarn according to claim 2, characterized in that The catalyst in step 2) is one or more of boric acid, triphenyl phosphite, sodium hypophosphite and sodium phosphite, and the addition amount is 0.2-0.8% of the total weight of caprolactam and the fatty chain diamine and 2,5-furandimethylamine.

4. The process for preparing a furan-based monomer-modified polyamide industrial yarn according to claim 1, characterized in that After extraction and vacuum drum drying, the relative viscosity of the furan monomer modified polyamide chips in step 3) is 2.8-3.6, and the water content is <400ppm.

5. The process for the preparation of furanyl monomer modified polyamide industrial yam as claimed in claim 1, wherein the process is characterized by In step 3), the spinning temperature is controlled at 280-300℃, the drawing process is realized by using multiple heating rollers to gradually increase the temperature and speed, and the temperature and speed of the drawing heating roller 1 are controlled at 40-60℃ and 600-900m / min, respectively, the temperature and speed of the drawing heating roller 2 are controlled at 70-100℃ and 1000-1800m / min, respectively, and the temperature and speed of the drawing heating roller 3 are controlled at 120-150℃ and 2000-3000m / min, respectively; after preliminary drawing, the product enters the heat setting process, and the temperature and speed of the heat setting roller are controlled at 160-180℃ and 3050-3600m / min, respectively; finally, the product is wound to form a shape, and the winding speed is controlled at 3000-3500m / min; the drawing ratio is calculated according to the speed ratio of the fastest heating roller to the slowest roller, and the drawing ratio is 5.0-6.0 times.