KR101130461B1 - Method for Recycling Wasted Nylon Fish Net and Recycled Nylon filament fiber - Google Patents

Abstract

The present invention relates to a method for recovering nylon waste fishing nets that can be recovered as a raw material by depolymerization of nylon waste fishing nets without dismantling or sorting, and to repeatedly recycle them, and to a method for producing recycled nylon filaments using the same, and a recycled nylon filament produced therefrom. .

Nylon waste fishing net, recycled nylon filament, depolymerization, ion exchange resin, oxidizing tablet, filtration, fractional distillation

Description

Method for Recycling Wasted Nylon Fish Net and Recycled Nylon filament fiber}

The present invention relates to a method for regeneration of nylon waste fishing nets and regenerated nylon filaments, and more specifically, to depolymerization of nylon waste fishing nets, through ion exchange resins, oxidation, refining and fractional distillation, to make lactam as a raw material with high purity of 99% or more. The present invention relates to a method for reclaiming nylon waste fishing nets that can be recovered and to a regenerated nylon filament.

In recent years, global warming due to environmental pollution has caused serious damages such as various natural disasters, and various efforts and international cooperation have been actively made to regulate or reduce greenhouse gas emissions. Since waste emits a large amount of harmful gases when incinerated, the ratio of greenhouse gas emissions is relatively high. Therefore, promoting recycling of waste is studied as an alternative.

However, these existing regeneration methods still have many problems to solve, and have the following problems, and are not an effective alternative.

First, huge facilities and personnel are invested in recovery and sorting. Due to the high amount of impurities in the recovered waste materials, many people and equipment are invested in the recovery and sorting of the recovered waste materials.

Another problem is the poor quality of the recycled raw materials. As described above, despite the enormous cost of recycling the waste, the purity of the recycled raw material is insufficient, so that it is mixed with a new raw material or developed only for a low-grade use.

Nylon is widely used for textiles, but it is also used for various industrial uses such as tire cords, fishing ropes, and films, and is increasingly used in plastics.

Generally, nylon products are not recycled to the raw material state of materials like glass or resin products. This is because, in the case of nylon products, it is difficult to disassemble and sort the finished product to a renewable level due to mixing with various other materials. However, industrial fabric has many petroleum-based materials such as polyester and nylon, and needs to be recycled in terms of resource saving and recycling.

The present invention is to overcome the above-mentioned problems of the prior art, one object of the present invention can be easily recovered in the raw material state of the material using a nylon waste fishing net, maintain a good quality of the new level, repeated regeneration This is to provide a possible method for the production of nylon waste.

Another object of the present invention relates to a method for producing a nylon long fiber of high quality from nylon waste fishing net.

It is yet another object of the present invention to provide a new level of reclaimed nylon filament which is produced by polymerizing and spinning the regenerated nylon chip.

One aspect of the present invention for achieving the above object is

Adding pyridine and an industrial detergent to the nylon waste fishing net and washing with industrial water;

Adding phosphoric acid to the nylon waste fishing net and depolymerizing by heating with hot steam to produce depolymerized lactam water;

Adding potassium permanganate and activated carbon to depolymerized lactam water, followed by oxidation and purification;

Filtering the oxidized depolymerized lactam water using a filter coated with diatomaceous earth;

Treating the filtered lactam water with (-) ion exchange resin, (+) ion exchange resin, and (-) ion exchange resin in this order;

Adding an aqueous sodium hydroxide solution to the depolymerized lactam water treated with ion exchange resin, and then subjecting to primary fractional distillation;

Second or third fractional distillation of the first fractionated depolymerized lactam; And

It relates to a method for producing a nylon recycle chip comprising the step of polymerizing and molding the secondary or tertiary fractionated depolymerization lactam.

Another aspect of the present invention for achieving the above object relates to a method for producing a recycled nylon filament, characterized in that to obtain a nylon filament by spinning a recycled nylon chip obtained by the recycle method of the nylon waste fishing net of the present invention will be.

Another aspect of the invention relates to a recycled nylon filament obtained by spinning or spinning-stretching, spinning-flamming the polymerized nylon recycled chip using a conventional spinning device.

According to the method of the present invention, nylon waste, especially waste fishing nets, can be easily depolymerized and recovered as a raw material without separate disintegration or screening, and can be repeatedly recycled. Can be obtained. Therefore, according to the present invention can contribute to resource saving and environmental pollution. In addition, the nylon filament produced using the nylon regenerated chip produced by the present invention is very excellent in fairness, dyeability and productability can be used in various applications such as new.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

In the case of regenerating the nylon waste fishing net according to the present invention, first, phosphoric acid is added to the nylon waste fishing net and then depolymerized by heating with hot steam. At this time, in order to remove various foreign matters such as dyes, salts, metals and other foreign material resin formations, pyridine, industrial detergents, etc. may be added to the nylon waste fishing net prior to depolymerization. Oxidized and purified by adding potassium permanganate and activated carbon to the depolymerized lactam water. The oxidized depolymerized lactam water was filtered using a filter coated with diatomaceous earth, treated with (-) ion exchange resin, (+) ion exchange resin, and (-) ion exchange resin in that order, and then depolymerized with ion exchange resin. The first fractional distillation was carried out by adding an aqueous sodium hydroxide solution to the lactam water. The first fractionated depolymerized lactam is subjected to the second or third fractional distillation to increase the purity. Secondary or tertiary fractionated depolymerized lactams can be polymerized and pelletized in a conventional manner to be regenerated into nylon chips.

Next, with reference to the drawings, each step of the present invention will be described in more detail. 1 is a process flow chart for explaining a method for recycling nylon waste fishing net according to the present invention.

First, nylon is depolymerized under specific conditions, and prior to depolymerization, it can be cut and washed to remove various foreign matters such as dyes and salts contained in nylon waste fishing nets, and other foreign matters such as metal or foreign material resin formation (S0). . At this time, in order to effectively remove salts, dyes and other foreign substances remaining in the waste fishing net, 5 to 30% by weight of pyridine and 1 to 5% by weight of industrial detergent are added to the weight of nylon waste fishing net, and industrial water is added 1 to 10 times to remove the industrial cleaner. Washing is performed within about 30 minutes under an internal temperature of 60 to 90 ° C. When the amount of pyridine added is less than 5% by weight compared to the nylon waste fishing net, it is not easy to remove impurities such as dyes, and when it exceeds 30% by weight, the economical efficiency may be reduced. If the added amount of the industrial detergent is less than 1% by weight compared to the nylon waste fishing net, it is not easy to remove the salt and other attached impurities. If the amount exceeds 5% by weight, the detergent may not be easily washed and the economic efficiency may be lowered. If industrial water is less than 1 times the weight of nylon waste fishing net, the cleaning effect is lowered, if it exceeds 10 times, economic efficiency may be lowered. If the internal temperature of the industrial scrubber is less than 60 ℃ during cleaning, the cleaning effect is inferior, if more than 90 ℃ may require additional equipment investment costs and economic efficiency may be lowered.

In the depolymerization step (S1), 0.1 to 5.0% by weight of phosphoric acid (H ₃ PO ₄ ) is added to the nylon waste fishing net and depolymerized for 4 to 12 hours by heating with hot steam at 250 to 400 ° C. At this time, when the content of phosphoric acid (H ₃ PO ₄ ) is less than 0.1% by weight, the depolymerization reaction rate is too slow, and when it exceeds 5.0% by weight, a problem of peroxidation may occur and economical efficiency may be lowered.

After the depolymerization treatment, an oxidation step and a purification step are performed. Specifically, 0.1 to 1.0% by weight of potassium permanganate (KMnO ₄ ) and 0.05 to 0.5% by weight of activated carbon are added to the depolymerized lactam water, and 1 to 1 at a temperature of 40 to 80 ° C. The depolymerized lactam water is oxidized and purified for 8 hours. At this time, the amount of potassium permanganate added is suitably 0.1 to 1.0% by weight of the depolymerized lactam water. If the amount of potassium permanganate added is less than 0.1% by weight, the oxidation effect is deteriorated and unsaturated compounds remain and the quality is lowered. When the amount of potassium permanganate exceeds 1.0% by weight, the acidity is too high compared to the effect, which may adversely affect the quality. The addition amount of activated carbon is suitably 0.05 to 0.5% by weight. If the amount of activated carbon added is less than 0.05% by weight, the purification effect is lowered. If the amount of activated carbon is more than 0.5% by weight, the amount of activated carbon remaining in the depolymerized lactam water may be too high, thereby reducing economic efficiency.

The deoxidized depolymerized lactam water was filtered under reduced pressure through an Oliver filter.

At this time, the Oliver filter is a vacuum cylindrical filter, the filter cotton cloth having fine pores is wound in a porous cylinder, and then coated with diatomaceous earth 5 to 30 cm.

Subsequently, the depolymerized lactam water is treated with (-) ion exchange resin, (+) ion exchange resin, and (-) ion exchange resin in this order (S2). At this time, it is preferable to treat in order of (-) ion exchange resin, (+) ion exchange resin, and (-) ion exchange resin in an effective aspect, and the residence time for each ion exchange resin is appropriately set to 3 to 20 minutes. . If the residence time for each ion exchange resin is less than 3 minutes, the ion exchange resin treatment effect is reduced, and when the treatment time exceeds 20 minutes, the effect is reduced compared to the residence time.

Subsequently, 0.05 to 1.00% by weight of an aqueous solution of sodium hydroxide having a concentration of 25% by weight was added to the deionized lactam water treated with ion exchange resin, followed by distillation at a temperature of 100 to 150 ° C and a vacuum of 200 to 600 torr for 1 to 10 hours. The depolymerized lactam is first fractionated at a temperature of 150 to 200 ° C. and a vacuum of 200 to 600 torr. The concentration of the aqueous sodium hydroxide solution is 25% by weight in general in a liquid state, it is convenient to use because it is a liquid state. If the amount of sodium hydroxide is less than 0.05% by weight, it is insufficient to neutralize the depolymerized oxide, and if it is more than 1.00% by weight, there may be a problem of overbased. When the water distillation, the temperature is 100 to 150 ℃, the vacuum is suitable for 200 to 600 torr. If the temperature is less than 100 ° C. and less than 200 torr vacuum, it is difficult to effectively evaporate water. If the temperature is more than 150 ° C. and more than 600 torr vacuum, lactam may be evaporated to lower the yield of lactam finally recovered.

After the first fractional distillation is completed, secondary fractional distillation is carried out to reduce the content of foreign matter to a minimum and to ensure the purity of the lactam. The first fractionated depolymerized lactam was again distilled at a temperature of 100 to 150 ° C. and a vacuum of 200 to 600 torr for 1 to 10 hours to remove residual water, and a depolymerized lactam at a temperature of 150 to 200 ° C. and a vacuum of 200 to 600 torr. Secondary fractional distillation. At this time, if the conditions of the secondary fractional distillation are less than 100 ℃ and less than 200 tor vacuum, it is difficult to effectively evaporate the water, and if the temperature is more than 150 ℃ and more than 600 torr vacuum, the lactam is evaporated to reduce the yield of the lactam finally recovered. have. After the second distillation, if the quality and purity of the distilled lactam are inferior, the third distillation may be performed by the same method as the second distillation method to improve the quality and purity of the distilled lactam.

Through the above purification and distillation process, it is possible to recover up to 99% of lactam as a raw material. Since the depolymerized lactam obtained in this way is of high purity, it can be made into nylon recycle chips by mixing 20 to 80% by weight alone or compared to a new lactam, polymerizing using a conventional polymerization apparatus, and then molding into pellets. When the polymerization, titanium dioxide may be mixed with 0.1 to 3% by weight, polymerized, and then molded into pellets to prepare nylon recycle chips.

Titanium dioxide is a matting agent, and when mixed to less than 0.1% by weight, the matting effect is reduced, and when mixed with 3% by weight or more, the spinning and post-processing processability is lowered.

Nylon recycled chips may be used alone without mixing with new products, but when the new chips are mixed, the quality may be further improved for long fiber spinning.

Another aspect of the invention relates to a process for producing recycled nylon filaments obtained by spinning or spinning-stretching, spinning-flamming a polymerized nylon recycled chip using conventional spinning equipment. Another aspect of the present invention can spun the nylon recycled chip either alone or in combination with the new nylon chip upon spinning into the long fibers.

Another aspect of the invention relates to a regenerated nylon filament obtained by the process. Such regenerated nylon filaments may have circular (○), triangular (△) or cross (+) cross sections. Such regenerated nylon filaments can be recycled for the same use as general nylon because of excellent processability, dyeability, and productability.

Hereinafter, the present invention will be described in more detail with reference to specific examples, but these examples are only intended to illustrate embodiments of the present invention and are not intended to limit the scope of the present invention.

Example  1: manufacture of recycled nylon chips and yarns

After the nylon waste fishing nets were cut into suitable sizes (30-100 cm each), 10 kg of the cut nylon waste fishing nets were put into an industrial scrubber. After washing with industrial water for 30 minutes in an industrial scrubber at an internal temperature of 80 ° C., it was dehydrated. At the time of washing, 10% by weight of pyridine and 2% by weight of industrial detergent were added to the weight of the waste fishing net.

Phosphoric acid (H ₃ PO ₄ ) was added 1.0% by weight to the washed nylon waste fishing net and heated with high temperature steam at 350 ° C. to conduct depolymerization for 6 hours. Subsequently, 0.5% by weight of potassium permanganate (KMnO ₄ ) and 0.15% by weight of activated carbon were added to the depolymerized lactam water, and the depolymerized lactam water was oxidized and purified for 4 hours at a temperature of 60 ° C. The oxidized depolymerized lactam water was filtered using an Oliver filter coated with diatomaceous earth, and then treated with (-) ion exchange resin, (+) ion exchange resin, and (-) ion exchange resin in turn for 6 minutes. 0.5 wt% of a 25 wt% sodium hydroxide aqueous solution was added to the filtered depolymerized lactam water, and the water was removed by distillation at a temperature of 120 ° C. and a vacuum of 400 torr for 4 hours, and then depolymerized lactam under a temperature of 180 ° C. and a vacuum of 400 torr. Was fractionated first. Subsequently, the first fractionated depolymerized lactam was absorbed with water, further distilled under a temperature of 120 ° C. and 400 torr for 4 hours to remove residual water, followed by depolymerization lactam at a temperature of 180 ° C. and a vacuum of 400 tor. Differential distillation was performed. The second fractional depolymerization lactam was further subjected to the third fractional distillation in the same manner as the second fractional distillation. Titanium dioxide was mixed with 1.5 wt% of the third fractionated lactam, polymerized using a conventional polymerization apparatus, and molded into pellets to prepare a nylon regenerated chip.

The polymerized nylon regenerated chip was spun at a spinning temperature of 260 ° C. and a spinning speed of 4,000 m / min using a spinning device to prepare a regenerated nylon filament.

The physical properties and processability of the third fractional lactam, regenerated nylon chip and regenerated nylon filament were evaluated and shown in Table 1 below.

Example  2: manufacture of recycled nylon chips and yarns

In the oxidation treatment of depolymerized lactam water, 1.0% by weight of potassium permanganate (KMnO ₄ ) and 0.3% by weight of activated carbon were added, and the depolymerized lactam water was oxidized and purified for 4 hours at a temperature of 60 ° C., followed by secondary fractional distillation. A nylon regenerated chip and a regenerated nylon filament were prepared in the same manner as in Example 1, except that 50% by weight of the new lactam was mixed with the lactam and polymerized without performing the third distillation. The properties and processability of the lactam, the regenerated nylon chip, and the regenerated nylon filament obtained by mixing the new lactam with 50% of the lactam recovered after the second distillation were shown in Table 1 together.

Comparative example  1: manufacture of recycled nylon chips and yarns

Phosphoric acid (H ₃ PO ₄ ) was added 1.0% by weight of nylon waste fishing nets and heated with high temperature steam at 350 ° C. to conduct depolymerization for 6 hours. Subsequently, 0.5% by weight of potassium permanganate (KMnO ₄ ) and 0.15% by weight of activated carbon were added to the depolymerized lactam water, and the depolymerized lactam water was oxidized and purified for 2 hours at a temperature of 50 ° C. The oxidized depolymerized lactam water was filtered using an Oliver filter coated with diatomaceous earth. The filtered depolymerized lactam water was distilled at 4O < 0 > C for 4 hours at 400torr vacuum to remove water, and the primary polymerization distillation of the depolymerized lactam was carried out at 180 占 폚 and 400torr vacuum. Subsequently, the first fractionated depolymerized lactam was absorbed with water, further distilled under a temperature of 120 ° C. and 400 torr for 4 hours to remove residual water, followed by depolymerization lactam at a temperature of 180 ° C. and a vacuum of 400 tor. Differential distillation was performed. Titanium dioxide was mixed with the secondary fractionated lactam by 1.5% by weight, polymerized using a conventional polymerization apparatus, and then molded into pellets to prepare a nylon regenerated chip.

The polymerized nylon regenerated chip was spun at a spinning temperature of 260 ° C. and a spinning speed of 4,000 m / min using a spinning device to prepare a regenerated nylon filament.

The physical properties and processability of the secondary fractional lactam, regenerated nylon chip and regenerated nylon filament were evaluated and shown in Table 1 below.

Comparative example  2: manufacture of recycled nylon chips and yarns

In the oxidation treatment of depolymerized lactam water, 1.0% by weight of potassium permanganate (KMnO ₄ ) and 0.3% by weight of activated carbon were added, and the depolymerized lactam water was oxidized and purified at a temperature of 50 ° C. for 2 hours, followed by secondary fractional distillation. A nylon regenerated chip and a regenerated nylon filament were prepared in the same manner as in Comparative Example 1 except that 50% by weight of a new lactam was mixed with lactam and polymerized. The properties and processability of the lactam, the regenerated nylon chip, and the regenerated nylon filament obtained by mixing the new lactam with 50% of the lactam recovered after the second distillation were shown in Table 1 together.

 [Property evaluation method]

* Depolymerization Lactam PM No . ( Permanganate No .):

Standard sample:
Sample containing KNnO ₄ solution with 0.01N concentration in 100ml of 20 ℃ distilled water

Measurement sample:
1 ml of lactam to be measured is added to 100 ml of distilled water at 20 ° C, and a sample containing KNnO ₄ solution of 0.01 N concentration is added.

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- How to measure:
Measure and record the number of seconds until the color of the measurement sample is the same as the standard sample.

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* Recycled Nylon Chip Viscosity (RV) :
Relative viscosity (RV) is measured at 25 ° C. with sulfuric acid as a solvent using an Ubelode viscometer.

* Color L and Color b value of regenerated nylon chip regenerated chip :
Using Color-view of Gardner, the color L value and the color b value of the reproducing chip were measured using the KS A 0067 color standard.

Elongation of recycled nylon filament :
The stiffness of the regenerated polyester filaments was measured using an Instron 5565 from Instron as assessed by the KS K 0412 standard.

* Radiation Operation :
A four-end spinner was operated for 48 hours, and the ratio of full pipe to total output was measured using a 4 kg volume basis.

* Cake appearance :
In light of the appearance of the cake, the appearance of the cake was determined to be good if the appearance of the yarn filament was clean without broken filament.

* Dyeing :
100 pieces of circular knitted fabrics were prepared by dyeing the fabrics with sock paper, and visually evaluated, there was no dyeing difference at all, and ◎, if there was at least one dyeing difference in the sample, X was indicated. The proportion of good samples without staining difference among the whole circular knitted fabrics was measured in% (%).

division Example 1 Example 2 Comparative Example 1 Comparative Example 2 Regenerative lactam PM No. 7,000 9,000 1,000 3,000 Nylon play chips Viscosity (RV) 2.58 2.61 2.56 2.59 Color l 89.1 90.6 86.3 87.5 Color b 2.0 1.5 3.8 3.2 play
nylon
Long fiber Radiation temperature
(℃) 260 260 260 260 Spinning speed
(m / min) 4,000 4,000 4,000 4,000 Den / Fila 40/34 40/34 40/34 40/34 Strength (g / d) 5.2 5.3 4.7 4.8 Shinto (%) 45 43 53 51 Radiation operation
(Commission rate,%) 97 98 88 90 Cake appearance Good Good Mouth occurrence Good Dyeability
(M rate,%) 98 99 85 88

As shown in Table 1, the regenerated chip and the regenerated nylon filament using the nylon regenerated lactam according to the examples are superior to the regenerated chip and the regenerated nylon filament using the nylon regenerated lactam according to the comparative example. It can be seen that.

Although the present invention has been described in detail with reference to preferred embodiments of the present invention, it will be apparent to those skilled in the art that the present invention may be variously changed or modified without departing from the spirit and scope of the present invention. Modifications and variations are also to be construed as being included in the scope of protection of the present invention.

1 is a process flowchart of a method for reproducing a nylon waste fishing net according to an embodiment of the present invention.

Claims (8)

Adding pyridine and an industrial detergent to the nylon waste fishing net and washing with industrial water; Adding 0.1 to 5.0% by weight of phosphoric acid to the nylon waste fishing net and depolymerizing for 4 to 12 hours by heating with hot steam at 250 to 400 ° C .; Adding 0.1 to 1.0% by weight of potassium permanganate and 0.05 to 0.5% by weight of activated carbon to the depolymerized lactam water, and then oxidizing and purifying for 1 to 8 hours at a temperature of 40 to 80 ° C; Filtering the oxidized depolymerized lactam water using a filter coated with diatomaceous earth; Treating the filtered depolymerized lactam water with (-) ion exchange resin, (+) ion exchange resin, and (-) ion exchange resin in sequence for 3 to 20 minutes, respectively; To the filtered depolymerized lactam water was added 0.05 to 1.00% by weight of an aqueous solution of sodium hydroxide at a concentration of 25% by weight, distilled for 1 to 10 hours at a temperature of 100 to 150 ° C and a vacuum of 200 to 600torr, and then water was removed. Primary fractional distillation at a temperature of from 200 ° C. to 200 to 600 torr; Subjecting the first fractionated depolymerized lactam to a second or third fractional distillation under the same conditions as the first fractional distillation; And A method for producing a nylon recycle chip, comprising the step of mixing and polymerizing secondary or tertiary fractionated depolymerized lactam with 0.1 to 3.0% by weight of titanium dioxide. delete delete delete delete A method for producing recycled nylon filaments, which comprises spinning nylon recycled chips prepared by the method of claim 1 to obtain nylon filaments. A method for producing a recycled nylon filament, characterized in that for spinning by mixing the nylon recycled chip produced by the method of claim 1 and a normal nylon chip. delete

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