KR101303819B1 - Recycled polyester filament having low melting property and antibacterial property - Google Patents

Abstract

The present invention is to depolymerize waste polyester using ethylene glycol as depolymerization catalyst to produce bis-2-hydroxyethyl terephthalate (BHET) as an intermediate, and to produce bis-2-hydroxyethyl terephthalate (BHET). After mixing the melting point modifier with a part, polycondensation was carried out again to obtain a regenerated low melting polyester, and the other part of the bis-2-hydroxyethyl terephthalate (BHET) was polycondensed as it was prepared from a general regenerated polyester. After that, an inorganic antimicrobial agent is added and kneaded to obtain a regenerated antimicrobial polyester having antimicrobial properties, and these are mixed spinning to obtain a low melting antimicrobial regenerated polyester filament and a method for producing the filament.

Description

Low melting point antimicrobial recycled polyester filament and its manufacturing method {RECYCLED POLYESTER FILAMENT HAVING LOW MELTING PROPERTY AND ANTIBACTERIAL PROPERTY}

The present invention is to depolymerize waste polyester using ethylene glycol as depolymerization catalyst to produce bis-2-hydroxyethyl terephthalate (BHET) as an intermediate, and to produce bis-2-hydroxyethyl terephthalate (BHET). After mixing the melting point modifier with a part, polycondensation was carried out again to obtain a regenerated low melting polyester, and the other part of the bis-2-hydroxyethyl terephthalate (BHET) was polycondensed as it was prepared from a general regenerated polyester. Thereafter, an inorganic antibacterial agent is added and kneaded thereto to obtain a regenerated antimicrobial polyester having antimicrobial properties, and the mixed spinning is performed to obtain a low melting antimicrobial regenerated polyester filament and a method for producing the filament.

The indoor and outdoor environment is the space where most people spend most of their time in their daily lives, and it is economically rich and improves the quality of life, so that the indoor environment includes various emotions and functional elements such as safety, functionality, comfort, and aesthetics. The demand for improvement is exploding. In particular, as environmental and safety regulations are strengthened in Korea and developed countries, strict standards for the performance of related products are being applied.

In addition, the material abundance gained through rapid economic growth under the mass production system has created serious harm such as resource depletion, environmental pollution, global warming, and ecosystem destruction in just one century. As a consensus for coexistence has been formed, the application of eco-friendly methods for the recycling of eco-friendly materials, limited resources, and minimizing environmental pollution is becoming a key trend in all industrial production, and the amount of waste generated as income increases and living standards improve. They are causing serious environmental pollution. Especially, waste synthetic resins account for about 15% of household waste, but many are foamed or blown, so they take up much more volume. It is a cause of smog and has a disadvantage in that it is hardly decomposed even when buried.

Therefore, in terms of environmental protection and recycling of resources, there is increasing interest in recycling waste synthetic resins rather than using degradable resins. In the case of advanced foreign countries, research on the recovery and recycling of useful resources from waste has already been carried out in various fields under long-term plans. In Korea, public awareness of environmental pollution has begun to emerge, and an economic recovery and recycling plan has been established, and related research is progressing.

Among general synthetic resins, polyester is the most widely used resin in textiles, films, food containers, etc., and the recycling of wastes such as waste polyesters generated during the process and waste polyesters such as beverage bottles discarded after use is a big concern. have.

Solidified polyesters are thermally unstable and it is almost impossible to reuse them after melting at temperatures above their melting point, so wastes must be recovered at lower temperatures. In the process of recovering the waste polyester, terephthalic acid (TPA), dimethyl terephthalate (DMT) and ethylene glycol (ethlyene glycol: EG), which are used as raw materials through depolymerization of waste polyester using a catalyst or the like. And a process of preparing bis-2-hydroxyethyl terephthalate (BHET), which is an intermediate product.

Among these processes, the process of recovering terephthalic acid, dimethyl terephthalate and ethylene glycol is a complicated process and takes a long time to recover terephthalic acid, dimethyl terephthalate and ethylene glycol by depolymerizing waste polyester, and the recovered terephthalic acid, dimethyl tere The process of producing regenerated polyester using phthalate and ethylene glycol has a disadvantage in that the procedure is complicated and takes a long time compared to the process of producing regenerated polyester with bis-2-hydroxyethyl terephthalate as an intermediate product. Therefore, a process for producing regenerated polyester recovering the intermediate bis-2-hydroxyethyl terephthalate has been developed, but regenerated polyester prepared from the recovered bis-2-hydroxyethyl terephthalate is recovered terephthalic acid and dimethyl. There was a problem that the physical properties or color is lower than the regenerated polyester made of terephthalate and ethylene glycol.

In addition, a general depolymerization process is performed by mixing and melting waste polyester and ethylene glycol to perform depolymerization, but the melting process of the waste polyester and ethylene glycol takes more than half of the entire process time for producing recycled polyester. Due to the melting time of, the production volume was lower than that of the general polyester manufacturing process, which prevented the recycling of waste polyester.

However, the biggest problem of the melting time that requires a long time is that if the depolymerization process and the polycondensation process are carried out in separate reactors, the reaction time of the depolymerization process and the polycondensation process is performed in a continuous circulation process at the production site. There is a problem that the process management is difficult because it does not have a long time. During the depolymerization process, the waiting time of the reaction tank during the polycondensation process becomes long, and the chemicals remaining in the reaction tank are solidified or carbonized and present as impurities in the polycondensation process. There was a problem of inhibiting the physical properties of the recycled polyester produced.

In addition, in recent years, the industrial field has a demand for eco-friendliness and complex functionalities, and in order to lead a healthy and comfortable life, various functionalities are required, and among them, antibacterial properties are particularly required.

Examples of the method for imparting antimicrobial properties to synthetic fibers include a method of adding an antimicrobial agent in a spinning step of fiberizing, and a method of copolymerizing a component having antimicrobial properties in a step of preparing a polymer for fiber (mainly a polymerization step). Synthetic fibers generally impart antimicrobial activity in the spinning step.

The present invention has been invented to solve the above problems, to recover the good bis-2-hydroxyethyl terephthalate from the waste polyester by depolymerization by using the waste polyester to be discarded by ethylene glycol, A portion of the recovered bis-2-hydroxyethyl terephthalate is used for depolymerization, which significantly shortens the total depolymerization process time, and further polycondenses the recovered bis-2-hydroxyethyl terephthalate to produce a regenerated low melting point polyester. A low melting point antimicrobial regenerated polyester filament obtained by adding an inorganic antimicrobial agent to a part of the regenerated low melting point polyester obtained, and producing a regenerated polyester having low melting point and antimicrobial properties and mixing and spinning them. And it aims to provide the manufacturing method.

In addition, waste bipolyester, especially waste polyester produced in the production line for producing polyester products, and waste polyester generated during cutting or other manufacturing processes are collected and depolymerized to obtain high quality bis-2-hydroxyethyl terephthalate. Was recovered and the same or similar physical properties of new low melting polyesters were obtained through polycondensation reaction using the recovered bis-2-hydroxyethyl terephthalate, and simultaneously having antimicrobial properties by the introduction of inorganic antimicrobial agents. It is an object of the present invention to provide a method for producing a regenerated low melting polyester using waste polyester to obtain a regenerated low melting polyester.

In addition, there is no problem in the salt processing process while having both low melting point eco-friendly and antimicrobial properties, and the purpose of manufacturing a low melting point antimicrobial recycled polyester that can replace the epoxy resin coating and fibers (fabric, warp knitting, circular knitting) using the same It is done.

The present invention relates to a method for producing a low-melting antimicrobial regenerated polyester filament using regenerated polyester, comprising: (1) depolymerizing the waste polyester by mixing and heating the waste polyester and ethylene glycol to produce bis-2-hydroxyethyl. Depolymerization step of obtaining terephthalate; (2) polycondensation of the bis-2-hydroxyethyl terephthalate obtained in the depolymerization step to obtain a regenerated polyester, wherein a part of the bis-2-hydroxyethyl terephthalate is polycondensed to produce a general regenerated polyester Preparing a regenerated antimicrobial polyester to obtain an antimicrobial low melting point polyester by adding and kneading an inorganic antimicrobial agent to the obtained general regenerated polyester; (3) polycondensing the bis-2-hydroxyethyl terephthalate obtained in the depolymerization step to obtain a regenerated polyester, after mixing another part of the bis-2-hydroxyethyl terephthalate with a melting point modifier. Preparing a regenerated low melting polyester obtained by polycondensation to obtain a regenerated low melting polyester; (4) mixing the regenerated antimicrobial polyester and the regenerated low melting point polyester in a weight ratio within a range of 12 to 20: 1; And (5) preparing filaments of 10 to 320 denier filaments by complex spinning and stretching into a sheath / core structure using a mixture obtained in the mixing step as a sheath part and a general polyester or regenerated polyester as a core part. It provides a method for producing a low melting antimicrobial recycled polyester filament, characterized in that consisting of.

Subsequent to the filament manufacturing step, the prepared filament may be further heat-treated to increase the crystallinity by heat-treating the prepared filament for 0.01 to 2 seconds on a roller surface of 60 to 150 ℃.

The depolymerization step may include a first depolymerization process of mixing waste polyester and ethylene glycol (EG) to produce bis-2-hydroxyethyl terephthalate (BHET); And bis-2-hydroxyethyl terephthalate (BHET) by mixing all or part of the bis-2-hydroxyethyl terephthalate (BHET) produced in the first depolymerization process with waste polyester and ethylene glycol (EG). It consists of a second depolymerization process to produce a, but consists of repeating only the second depolymerization process using a portion of the bis-2-hydroxyethyl terephthalate (BHET) produced in the second depolymerization process after the first depolymerization process. Can be.

In the depolymerization step, the first depolymerization process mixes the waste polyester and ethylene glycol in a molar ratio of 1.0: 0.1 to 2.0, pressurized to 1.5 to 2.5 kg / cm 2 using nitrogen (N ₂ ) gas, and 210 to After stirring for 1 to 4 hours by stirring at a speed of 10 to 50rpm at 240 ℃, the molten mixture is pressurized to 2.0 to 2.5kg / ㎠ using nitrogen gas, at a speed of 30 to 70rpm at 245 to 260 ℃ Depolymerization for 1.0 to 3.0 hours with stirring, and the secondary depolymerization process was performed by mixing waste polyester, ethylene glycol (EG) and bis-2-hydroxyethyl terephthalate in a molar ratio of 1.0: 0.1 to 2.0: 0.5 to 2.0. Pressurized at 1.5 to 2.5 kg / cm 2 using nitrogen gas, stirred at 210 to 240 ° C. at a speed of 10 to 50 rpm, and melt mixed for 30 to 50 minutes, and then the molten mixture was heated to 2.0 to 2.5 using nitrogen gas. ㎏ / ㎠ And pressing may be accomplished by stirring at 245 to 260 ℃ at a rate of 30 to 70rpm depolymerization for 1.0 to 3.0 hours.

The inorganic antimicrobial agent may be selected from the group consisting of silver-supported zirconium phosphate antimicrobials, silver or zinc-supported zeolite antibacterial agents, silver-supported calcium phosphate antimicrobials, or mixtures of two or more thereof.

The inorganic antimicrobial agent may be added in an amount in the range of 0.5 to 0.7% by weight based on the total weight of the regenerated low melting polyester.

According to the present invention, in the production line for producing a polyester product, the waste of the raw material and waste polyester generated during the cutting or other manufacturing process is collected to recover the good bis-2-hydroxyethyl terephthalate through depolymerization, The resulting bis-2-hydroxyethyl terephthalate (BHET) was again polycondensed to obtain regenerated low melting polyester, and inorganic antimicrobial agent was added to the regenerated low melting polyester obtained and kneaded to kneaded to have low melting point and antibacterial properties. There is an effect that can be used in the industry by obtaining a regenerated antimicrobial low melting point polyester having a, and mixed spinning them to obtain a filament which can be particularly useful in the production of filters and the like.

In addition, by recycling waste polyester, which was difficult to dispose, there is an effect of saving resources and protecting the environment.

1 is a photograph of the yarn cross-section and the shape after heat treatment of the low melting antibacterial polyester filament obtained according to one specific embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail. In describing the present invention, detailed descriptions of related well-known functions or configurations are omitted in order not to obscure the subject matter of the present invention.

The terms " about ", " substantially ", etc. used to the extent that they are used herein are intended to be taken to mean an approximation to or in the numerical value of the manufacturing and material tolerances inherent in the meanings mentioned, Accurate or absolute numbers are used to help prevent unauthorized exploitation by unauthorized intruders of the referenced disclosure.

Chemically recyclable polyesters include hydrolysis, which uses water to reduce monomers or oligomers, glycols such as ethylene glycol (EG) and propylene glycol (PG). And glycolysis using methanol, methanolysis using methanol, and the like.

Glycol glycolysis can be carried out in a batch or continuous process, is less expensive than methanolysis or hydrolysis, and can be applied to more applications than remelt injection.

Therefore, the present invention recovers bis-2-hydroxyethyl terephthalate (BHET) by depolymerizing waste polyester by glycolysis using ethylene glycol, and then lowering the melting point through polycondensation. The present invention relates to providing a regenerated polyester having properties of and antimicrobial properties, and spinning it to provide a low melting point antimicrobial regenerated polyester filament that can be usefully used for various purposes such as the manufacture of filters.

In the method for producing a low-melting antimicrobial regenerated polyester filament using regenerated polyester, (1) Bis-2-hydroxyethyl terephthalate is depolymerized by depolymerizing waste polyester and heating by mixing waste polyester with ethylene glycol. Depolymerization step to obtain; (2) polycondensation of the bis-2-hydroxyethyl terephthalate obtained in the depolymerization step to obtain a regenerated polyester, wherein a part of the bis-2-hydroxyethyl terephthalate is polycondensed to produce a general regenerated polyester Preparing a regenerated antimicrobial polyester to obtain an antimicrobial low melting point polyester by adding and kneading an inorganic antimicrobial agent to the obtained general regenerated polyester; (3) polycondensing the bis-2-hydroxyethyl terephthalate obtained in the depolymerization step to obtain a regenerated polyester, after mixing another part of the bis-2-hydroxyethyl terephthalate with a melting point modifier. Preparing a regenerated low melting polyester obtained by polycondensation to obtain a regenerated low melting polyester; (4) mixing the regenerated antimicrobial polyester and the regenerated low melting point polyester in a weight ratio within a range of 12 to 20: 1; And (5) preparing filaments of 10 to 320 denier filaments by complex spinning and stretching into a sheath / core structure using a mixture obtained in the mixing step as a sheath part and a general polyester or regenerated polyester as a core part. It provides a method for producing a low melting antimicrobial recycled polyester filament, characterized in that consisting of.

The depolymerization step of (1) comprises depolymerizing the waste polyester by mixing and heating the waste polyester and ethylene glycol to obtain bis-2-hydroxyethyl terephthalate. Depolymerization of the waste polyester is carried out as follows. First, the waste polyester is mixed with ethylene glycol (EG; ethylene glycol) as a catalyst and a solvent to obtain a first mixture. The waste polyester is a metal component, a synthetic resin of different components, etc. is removed from the collected waste polyester, and the waste polyester is pulverized into a flake shape having a size in the range of 1 to 20 mm using a pulverizer. The waste polyester may be finely pulverized to a size in the range of 1 to 5 mm to be easily melted, but the present invention is not limited to the flake shape as described above or the range of the size of the bar. Subsequently, the waste polyester in the first mixture is dissolved by heating to allow the waste polyester to react well with ethylene glycol as a catalyst and solvent as described above to promote depolymerization. Subsequently, the molten first mixture is depolymerized to produce bis-2-hydroxyethyl terephthalate (BHET). In the above depolymerization, the ethylene glycol decomposes the polyester into bis-2-hydroxyethyl terephthalate by depolymerization by the transesterification reaction with the waste polyester. The reaction rate of the depolymerization of the present invention depends on the temperature, catalyst, feedstock granularity and the amount of glycol. The final monomer composition is also determined by the decomposition reaction time and the duration after depolymerization. Lower amounts of glycol require higher temperatures and longer reaction times, resulting in higher molecular weight oligomers. In the depolymerization, in particular, the first mixture obtained by mixing the waste polyester and ethylene glycol (EG) in a molar ratio of 1.0: 0.1 to 2.0 is pressurized to 1.5 to 2.5 kg / cm 2 using nitrogen (N ₂ ) gas, and 210 to Melt for 3 to 4 hours while stirring at 240 ℃ 10 to 50 rpm, pressurized to 2.0 to 2.5 kg / ㎠ using nitrogen gas, 100 to 100 with stirring at a rate of 30 to 70 rpm at 225 to 260 ℃ Depolymerization for 180 minutes. The mixing ratio of the waste polyester and ethylene glycol may have a problem that the reaction time is too long when ethylene glycol is mixed with less than 0.1 mole with respect to 1 mole of the waste polyester, on the contrary, when it exceeds 2.0 moles, The amount of waste polyester administered to the depolymerization in the reaction vessel having an inner volume is reduced to reduce the productivity, there may be a problem that a relatively excessive energy is required for the depolymerization of the same amount of waste polyester. In the mixed waste polyester and ethylene glycol, the melted polyester starts to melt at about 210 ° C. by heating, and when the temperature is continuously increased to 230 to 240 ° C., the melting increases as the temperature rises. When the melting proceeds to some extent, the mixture is stirred at 10 to 50 rpm to prevent the carbonization of the compound by concentrating thermal energy in one place. After the melting time of the waste polyester and ethylene glycol is about 3 to 4 hours, the melting is completed, after the melting of the waste polyester is completed, pressurized to 2.0 to 2.5kg / ㎠ using nitrogen gas, The stirring speed is raised to 20 to 60 rpm and the temperature is raised to 225 to 260 ° C. so that the waste polyester promotes depolymerization through transesterification with ethylene glycol to produce bis-2-hydroxyethyl terephthalate. After the depolymerization step, a bis-2-hydroxyethyl terephthalate produced in the depolymerization step may be further filtered to remove the foreign matter. The filtering process is a process of removing bis-2-hydroxyethyl terephthalate generated by the depolymerization process through a filter to remove bis-2-hydroxyethyl terephthalate and removing bis-2-hydroxyethyl terephthalate after the filtering process. It is a process for reducing the productivity and the defective rate of a recycled polyester in the polycondensation process performed. In the filtering process, the filter preferably uses a filter of about 300 to 1500 mesh, and may be pressurized to 1.5 to 3.0 kg / cm 2 to shorten the filtering process time, but the present invention is not limited thereto. It will be understood by those skilled in the art that the selection of an appropriate filter and the appropriate degree of pressurization can be selected in consideration of the source of waste polyester and the degree of contamination of the waste polyester.

In particular, the depolymerization may be preferably composed of primary depolymerization and secondary depolymerization, wherein the primary depolymerization is performed by mixing the waste polyester and ethylene glycol (EG) in a molar ratio of 1.0: 0.1 to 2.0 and nitrogen (N ₂ ). Pressurized to 1.5 to 2.5kg / ㎠ using a gas and stirred at a speed of 10 to 50rpm at 210 to 240 ℃ by melt mixing for 1 to 4 hours, the molten mixture using 2.0 to 2.5kg / ㎠ using nitrogen gas And depolymerized for 1.0 to 3.0 hours while stirring at a rate of 30 to 70 rpm at 245 to 260 ° C., and the secondary depolymerization of waste polyester, ethylene glycol (EG) and bis-2-hydroxyethyl terephthalate in molar ratio 1.0 The mixture is mixed at 0.1 to 2.0: 0.5 to 2.0, pressurized to 1.5 to 2.5 kg / cm 2 using nitrogen gas, and stirred at 210 to 240 ° C. at a speed of 10 to 50 rpm to melt for 30 to 50 minutes, and then the molten mixture. Vagina That by using a gas pressurized to 2.0 to 2.5㎏ / ㎠ and depolymerization at 245 to 260 ℃ while stirring at a rate of 30 to 70rpm 1.0 to 3.0 hours, characterized.

Bis-2-hydroxyethyl terephthalate may be obtained by the depolymerization method according to the present invention as described above, and the bis-2-hydroxyethyl terephthalate is polycondensed with polyester again to regenerate low melting point. Polyesters can be obtained.

In the preparation of the regenerated antimicrobial polyester of (2), the bis-2-hydroxyethyl terephthalate obtained in the depolymerization step is polycondensed to obtain a regenerated polyester, wherein the bis-2-hydroxyethyl terephthalate Polycondensation of to obtain a general regenerated polyester, and to the obtained general regenerated polyester is added an inorganic antibacterial agent and kneaded to obtain an antimicrobial low melting point polyester. The conditions of the polycondensation here can be carried out the same or similar to the conditions of the polycondensation in the production of known polyester. The polycondensation is a process for producing a polyester with the bis-2-hydroxyethyl terephthalate. The bis-2-hydroxyethyl terephthalate is 30 to 90 rpm in a vacuum state in the same or similar manner to a general polyester manufacturing process. It may consist of heating to a temperature range of 245 to 290 ℃ 60 to 240 minutes while stirring. The vacuum state may be adjusted to be about 1.5 mbar or less at about 285 ° C. by performing the step as the polycondensation process starts and the temperature rises. In the polycondensation process, antimony oxide (Sb ₂ O ₃ ), titanium oxide, dibutyl tin dilaurate and the like may be used as the condensation catalyst, and antimony oxide may be preferably used. The antimony oxide may be used in an amount of 50 to 600 ppm based on the total amount of bis-2-hydroxyethyl terephthalate. When the amount of the antimony oxide used as the polycondensation catalyst is less than 50 ppm based on the total amount of bis-2-hydroxyethyl terephthalate, there may be a problem that the reaction rate is significantly lowered, on the contrary, exceeds 600 ppm. In this case, the reaction rate is too fast to increase the molecular weight distribution, and also may cause problems such as increasing the pack pressure by acting as a foreign material during spinning. In addition, the polycondensation step may be performed by adding a thermal stabilizer to the bis-2-hydroxyethyl terephthalate. As the heat stabilizer, phosphoric acid (H ₃ PO ₄ ) may be preferably used. The thermal stabilizer is added for the thermal stability of the bis-2-hydroxyethyl terephthalate. The phosphoric acid may be used in an amount of 100 to 400 ppm based on the total amount of bis-2-hydroxyethyl terephthalate. When the amount of the phosphoric acid used as the thermal stabilizer is less than 100 ppm based on the total amount of bis-2-hydroxyethyl terephthalate, there may be a problem that the heat resistance of the final polymer is lowered, and in contrast, it exceeds 400 ppm. In this case, there may be a problem that acts as a foreign material during spinning to increase the pack pressure, and lower the reaction activity of the catalyst. In addition, in the polycondensation, titanium dioxide (TiO ₂ ) or silicon dioxide (SiO ₂ ) may be further added as a quencher in an amount of 0.01 to 3% by weight based on the total amount of bis-2-hydroxyethyl terephthalate. . In the polycondensation, an antioxidant, an antibacterial agent, a deodorant, a fluorescent brightener, a polymerization stabilizer, or the like may be further added to any one or both of the cis portion or the core portion, and the addition of these additives is easy for those skilled in the art. It can be understood. In particular, this step consists of adding an inorganic antibacterial agent to the regenerated polyester obtained by the polycondensation and kneading to obtain an antimicrobial low melting polyester. The inorganic antimicrobial agent is an inorganic antimicrobial agent which substitutes metal ions such as silver, copper and zinc to inorganic carriers such as zeolite and silica alumina, and has a three-dimensional skeletal structure with fine pores. great. On the other hand, metals that are toxic to microorganisms are generally toxic to humans in general, but metals such as silver, copper, and zinc are one of the few metals with strong antibacterial activity and high stability. Depending on the type of carrier and its binding state, the amount of active oxygen ions generating antibacterial activity is different. Inorganic antimicrobial agents have high heat resistance compared to conventional organic antimicrobial agents, and have high stability such as not causing volatilization and decomposition, and thus can be applied to a wide range of applications. Since the antimicrobial effect of the inorganic antibacterial agent is expressed by active oxygen ions, there is no immediate effect due to the elution of the drug, but it has a long-lasting effect and does not generate resistant bacteria. The inorganic antimicrobial agent may be preferably selected from the group consisting of a silver-supported zirconium phosphate antimicrobial agent, a silver or zinc-supported zeolite antimicrobial agent, a silver-supported calcium phosphate antimicrobial agent or a mixture of two or more thereof. The inorganic antimicrobial agents can be understood by those skilled in the art to the extent that they can be purchased and used commercially from leading manufacturers at home and abroad. For example, the silver-supported zirconium phosphate antibacterial agent may be used by purchasing the product name NOVARON AGT-330S of TOAGOSEI Co. LTD of Japan. The silver or zinc supported zeolite antimicrobial agent is disclosed in Korean Patent Publication No. 10-0492751, which is known to those skilled in the art. The inorganic antimicrobial agent may be preferably added in an amount of 0.5 to 0.7% by weight based on the total weight of the regenerated low melting polyester. When the inorganic antimicrobial agent is added in less than 0.5% by weight, there may be a problem that the provision of antimicrobial activity is not sufficient, on the contrary, when the inorganic antimicrobial agent exceeds 0.7% by weight, it may be difficult to control the antimicrobial content.

In the preparing of the regenerated low melting polyester of (3), the bis-2-hydroxyethyl terephthalate obtained in the depolymerization step is polycondensed to obtain a regenerated polyester, wherein the bis-2-hydroxyethyl tere Another portion of the phthalate consists of mixing with the melting point modifier followed by polycondensation to yield a regenerated low melting polyester. In particular, this step is a regenerated low melting polyester obtained by polycondensing the bis-2-hydroxyethyl terephthalate obtained in the depolymerization step with a melting point modifier selected from the group consisting of polyethylene glycol, isophthalic acid or mixtures thereof. To obtain. The conditions of the polycondensation here are the same as the conditions of the polycondensation in the production step of the regenerated antimicrobial polyester of the above (2) except that the melting point modifier is mixed with the bis-2-hydroxyethyl terephthalate and polycondensed. The same or similar may proceed, and thus repeated description will be omitted for simplicity. The melting point modifier may be selected from the group consisting of polyethylene glycol, isophthalic acid, or mixtures thereof to lower the melting point of the polyester and prevent crystallization. It is to be obtained as a regenerated polyester having the property of a regenerated low melting point polyester.

According to the present invention, a post-treatment step such as a chip manufacturing step may be further included after the step of preparing the regenerated antimicrobial polyester of (2) and / or the step of producing the regenerated low melting point polyester of (3). . The chip manufacturing step is a process of manufacturing a chip to facilitate the use of the recycled low melting point polyester produced in the polycondensation step, the size of the chip can be produced in a variety of sizes depending on the industrial field used, such a chip Preparation and control of the size and shape of the chip and the like will be readily understood by those skilled in the art.

The mixing step of (4) consists of mixing the regenerated low melting point polyester and the regenerated antimicrobial polyester in a ratio of 12 to 20: 1 by weight. Here, if the regenerated low-melting polyester is less than 12 weights based on 1 weight of the regenerated antimicrobial polyester, there may be a problem that the antimicrobial properties are not expressed, on the contrary, if the weight exceeds 20 weights, the production cost is increased. There may be a problem.

The filament manufacturing step of (5) is the filament of 10 to 320 denier (compound spinning and stretching) in the sheath / core structure using the mixture obtained in the mixing step as the sheath part and the general polyester or regenerated polyester as the core part It is made to prepare. It is to be understood that such filament manufacturing steps are well known to those skilled in the art.

In addition, a heat treatment step of increasing the degree of crystallinity by heat-treating the prepared filament for 0.01 to 2 seconds on the surface of the roller (roller) of 60 to 150 ℃ following the filament manufacturing step. The heat treatment step is also to be carried out in the manufacture of a conventional PET filament, it will be understood to be known to those skilled in the art can be easily carried out. In the above heat treatment temperature is less than 60 ℃ or heat treatment time

The depolymerization step may include a first depolymerization process of mixing waste polyester and ethylene glycol (EG) to produce bis-2-hydroxyethyl terephthalate (BHET); And bis-2-hydroxyethyl terephthalate (BHET) by mixing all or part of the bis-2-hydroxyethyl terephthalate (BHET) produced in the first depolymerization process with waste polyester and ethylene glycol (EG). It consists of a second depolymerization process to produce a, but consists of repeating only the second depolymerization process using a portion of the bis-2-hydroxyethyl terephthalate (BHET) produced in the second depolymerization process after the first depolymerization process. Can be.

In the depolymerization step, the first depolymerization process mixes the waste polyester and ethylene glycol in a molar ratio of 1.0: 0.1 to 2.0, pressurized to 1.5 to 2.5 kg / cm 2 using nitrogen (N ₂ ) gas, and 210 to After stirring for 1 to 4 hours by stirring at a speed of 10 to 50rpm at 240 ℃, the molten mixture is pressurized to 2.0 to 2.5kg / ㎠ using nitrogen gas, at a speed of 30 to 70rpm at 245 to 260 ℃ Depolymerization for 1.0 to 3.0 hours with stirring, and the secondary depolymerization process was performed by mixing waste polyester, ethylene glycol (EG) and bis-2-hydroxyethyl terephthalate in a molar ratio of 1.0: 0.1 to 2.0: 0.5 to 2.0. Pressurized at 1.5 to 2.5 kg / cm 2 using nitrogen gas, stirred at 210 to 240 ° C. at a speed of 10 to 50 rpm, and melt mixed for 30 to 50 minutes. ㎏ / ㎠ And pressing may be accomplished by stirring at 245 to 260 ℃ at a rate of 30 to 70rpm depolymerization for 1.0 to 3.0 hours.

Examples of the method for producing the regenerated low melting polyester fibers of the present invention are shown below, but not limited thereto.

Manufacturing example  One ; In depolymerization  by Vis -2- Of hydroxyethyl terephthalate  Produce

The collected waste polyester is collected and ground to an average size of 2.5 mm, and pulverized into flakes. The pulverized waste polyester and ethylene glycol (EG) are mixed in a molar ratio of 1.0: 0.25, and nitrogen gas is mixed. Pressurized to 2.0 kg / cm 2, and stirred at a rate of 18 rpm at about 235 ° C. to continue heating for about 2 hours until the spent polyester flakes were completely melted. The molten mixture was pressurized to 2.5 kg / cm 2 using nitrogen gas, continuously heated to 255 ° C., and depolymerized with stirring at a speed of 56 rpm to obtain bis-2-hydroxyethyl terephthalate in oligomer form. The foreign material was removed through the filter, and the obtained bis-2-hydroxyethyl terephthalate was used in the following examples.

Manufacturing example  2 ; Preparation of Regenerative Antimicrobial Polyester

As bis-2-hydroxyethyl terephthalate (BHET) polymerization conditions obtained in Preparation Example 1, an esterification reaction temperature of about 235 ° C, an esterification reaction time of about 210 minutes, a polycondensation reaction temperature of about 270 ° C, and a polycondensation reaction Polycondensation was carried out by polycondensation under the conditions of polycondensation used in the production of ordinary polyester for about 210 minutes, to prepare a regenerated polyester, and 10 parts by weight of a zirconium phosphate-based antimicrobial agent was added to 90 parts by weight of the regenerated polyester as an inorganic antibacterial agent, followed by kneading. To prepare a masterbatch (chip) of regenerated antimicrobial polyester. At this time, the zirconium phosphate-based antimicrobial agent was used an antimicrobial agent containing 25% by weight of silver (Ag).

Manufacturing example  3; play Low melting point  Production of polyester

To bis-2-hydroxyethyl terephthalate (BHET) obtained in Preparation Example 1 was added 256 kg of isophthalic acid and 8.7 kg of polyethylene glycol-4000 based on 1 ton of PET as a melting point modifier. The reaction temperature was about 235 ° C., the esterification time was about 210 minutes, the polycondensation reaction temperature was about 270 ° C., and the polycondensation reaction time was about 210 minutes. Prepared to obtain a regenerated low melting polyester having a low melting point characteristic having a melting point of about 160 ℃.

Example  One

Composite spinning is carried out in the form of sheath / core using composite spinning, and the sheath portion is mixed with the regenerated low melting point polyester and the regenerated antimicrobial polyester at a ratio of 18: 1. Polyester was spun complex. A low melting point antimicrobial poly for interior was produced by spinning at 270 ° C. on a regenerated low-melting polyester part of the sheath and stretching it at a draw ratio of 3.0 at 75 ° C. to a 75 denier filament with a single yarn number of 24, followed by heat treatment at 120 ° C. for 0.03 seconds. Ester filaments were prepared.

Fig. 1 shows photographs taken of the yarn cross section and the shape after heat treatment of the obtained low melting antibacterial polyester filament.

Subsequently, the fabric was fabricated by oblique sizing using the manufactured filament, and the binding was performed by heat treatment at 200 ° C. × 40 m / m during the dyeing process.

Example  2

The same process as in Example 1 was performed, but the regenerated low-melting point polyester and the regenerated antimicrobial polyester were mixed in a ratio of 18: 1, and the core part was spliced with regenerated polyester. Was prepared.

Example  3

It was prepared in the same manner as in Example 2, but the circular piece was prepared using the filament prepared above.

Example  4

Prepared in the same manner as in Example 3, but prepared a warp knitted using the filament prepared above.

Comparative example  One

After spinning at 270 ° C. to the site where no antimicrobial agent was added, drawing at 75 ° C. at a draw ratio of 3.0 to prepare 75 denier filaments of single yarn number 24, and then heat-treating at 120 ° C. for 0.03 seconds to prepare low-melting polyester filament for interior use. It was. The fabric was fabricated by oblique sizing using the manufactured filament, and the binding was performed by heat treatment at 200 ° C. X 40 m / m during the dyeing process.

Comparative example  2

Although manufactured in the same manner as in Comparative Example 1, a filament was prepared by composite spinning a low melting point polyester on the sheath part and a regenerated polyester on the core part. The fabric was fabricated by oblique sizing using the manufactured filament, and the binding was performed by heat treatment at 200 ° C. X 40 m / m during the dyeing process.

※ Measurement of physical properties of Examples and Comparative Examples

The physical properties of the intrinsic viscosity (IV) and melting point (Tm) of the polyester chips of the above examples and comparative examples were measured by a conventional method.

In addition, the strength and elongation of the filament of 75 denier prepared in Examples and Comparative Examples was measured, and the antimicrobial activity of the polyester filaments of Examples and Comparative Examples was measured by the KS K 0693 method. The above measured values are shown in Table 1.

division IV
(㎗ / g) Tm (占 폚) burglar
(g / d) Shinto (%) Antimicrobial activity Example 1 0.678 180.1 4.9 25-29 99.9 Example 2 0.675 180.2 5.0 28 to 30 99.9 Example 3 0.675 180.2 5.0 28 to 30 99.9 Example 4 0.675 180.2 5.0 28 to 30 99.9 Comparative Example 1 0.680 180.2 4.9 25-28 70.1 Comparative Example 2 0.678 180.2 4.9 26-29 70.2

division Standard fabric (cotton) Example 1 Example 2
Strain 1
(Bacterial number / ml) Initial strain 2.0 x 10 ⁴ 2.0 x 10 ⁴ 2.0 x 10 ⁴ 18 hours later 8.9 x 10 ⁶ Less than 10 Less than 10 increase 445 times increase 99.9% decrease 99.9% decrease
Strain 2
(Bacterial number / ml) Initial strain 2.2 x 10 ⁴ 2.2 x 10 ⁴ 2.2 x 10 ⁴ 18 hours later 7.2 x 10 ⁷ Less than 10 Less than 10 increase 3873 times increase 99.9% decrease 99.9% decrease

Used strain:

Strain 1: Staphylococcus aureus ; ATCC 6538)

Strain 2: Klebsiella pneumoniae ; ATCC 4352)

As shown in Table 2, it can be seen that the number of strains decreased to 99.9% after 18 hours in the fabric prepared in Examples. Therefore, it can be seen that the antimicrobial activity of the low melting point antimicrobial polyester filament according to the present invention is very excellent.

The present invention can be used in the industry for producing and processing low-melting polyester, and can be used in the industry for manufacturing filters, antibacterial fabrics, and the like.

(No sign)

Claims (7)

In the manufacturing method of low melting antibacterial regenerated polyester filament using regenerated polyester,
(1) a depolymerization step of depolymerizing the waste polyester by mixing and heating the waste polyester and ethylene glycol to obtain bis-2-hydroxyethyl terephthalate;
(2) polycondensation of the bis-2-hydroxyethyl terephthalate obtained in the depolymerization step to obtain a regenerated polyester, wherein a part of the bis-2-hydroxyethyl terephthalate is polycondensed to produce a general regenerated polyester Preparing a regenerated antimicrobial polyester to obtain an antimicrobial low melting point polyester by adding and kneading an inorganic antimicrobial agent to the obtained general regenerated polyester;
(3) polycondensing the bis-2-hydroxyethyl terephthalate obtained in the depolymerization step to obtain a regenerated polyester, after mixing another part of the bis-2-hydroxyethyl terephthalate with a melting point modifier. Preparing a regenerated low melting polyester obtained by polycondensation to obtain a regenerated low melting polyester;
(4) mixing the regenerated antimicrobial polyester and the regenerated low melting point polyester in a weight ratio within a range of 12 to 20: 1; And
(5) A filament manufacturing step of producing a filament of 10 to 320 denier by complex spinning and stretching into a sheath / core structure using the mixture obtained in the mixing step as a sheath part and a general polyester or regenerated polyester as a core part. ;
Method for producing a low melting antibacterial regenerated polyester filament comprising a. The method of claim 1,
Subsequent to the filament manufacturing step of the filament produced by the heat treatment for 0.01 to 2 seconds on the surface of the roller (roller) of 60 to 150 ℃ further comprises a heat treatment step of increasing the crystallinity of the low melting point antimicrobial regenerated polyester filament Manufacturing method. The method of claim 1,
The depolymerization step is a first depolymerization step of producing bis-2-hydroxyethyl terephthalate (BHET) by mixing waste polyester and ethylene glycol (EG); And bis-2-hydroxyethyl terephthalate (BHET) by mixing all or part of the bis-2-hydroxyethyl terephthalate (BHET) produced in the first depolymerization process with waste polyester and ethylene glycol (EG). It consists of a second depolymerization process to produce a, but consists of repeating only the second depolymerization process using a portion of the bis-2-hydroxyethyl terephthalate (BHET) produced in the second depolymerization process after the first depolymerization process. Method for producing a low melting antimicrobial recycled polyester filament, characterized in that. The method of claim 3, wherein
In the first depolymerization process, the waste polyester and ethylene glycol are mixed at a molar ratio of 1.0: 0.1 to 2.0, pressurized to 1.5 to 2.5 kg / cm 2 using nitrogen (N ₂ ) gas, and 10 to 210 to 240 ° C. After stirring for 1 to 4 hours by stirring at a rate of 50 to 50rpm, the molten mixture is pressurized to 2.0 to 2.5kg / ㎠ using nitrogen gas, 1.0 to while stirring at a rate of 30 to 70rpm at 245 to 260 ℃ Depolymerize for 3.0 hours,
In the second depolymerization process, waste polyester, ethylene glycol (EG) and bis-2-hydroxyethyl terephthalate are mixed in a molar ratio of 1.0: 0.1 to 2.0: 0.5 to 2.0, and 1.5 to 2.5 kg using nitrogen gas. / Cm 2, the mixture was stirred at 210 to 240 ° C. at a speed of 10 to 50 rpm and melt mixed for 30 to 50 minutes. Then, the molten mixture was pressurized to 2.0 to 2.5 kg / cm 2 using nitrogen gas and 245 to 260 ° C. Process for producing a low melting antimicrobial regenerated polyester filament characterized in that the depolymerization for 1.0 to 3.0 hours while stirring at a rate of 30 to 70rpm. The method of claim 1,
The inorganic antibacterial agent is selected from the group consisting of silver-supported zirconium phosphate antimicrobial agent, silver- or zinc-supported zeolite antimicrobial agent, silver-supported calcium phosphate antimicrobial agent or a mixture of two or more thereof. The method of claim 5, wherein
The inorganic antimicrobial agent is a method for producing a low melting point antimicrobial regenerated polyester filament, characterized in that contained in an amount of 0.5 to 0.7% by weight based on the total weight of the regenerated low melting point polyester. A low melting antimicrobial recycled polyester filament made according to any one of claims 1 to 6.

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