KR20220003410A - Recycled fiber, Composite for vehicle and method for preparing the same - Google Patents

Abstract

The present application relates to a recycled fiber and a vehicle material including the same. The recycled fiber of the present application is environmentally friendly, including recycled PET, and satisfies the properties of commercially required materials for vehicles. The present invention relates to the recycled fiber which comprises 25 to 95 wt% of recycled polyethylene terephthalate (PET) having an intrinsic viscosity of greater than 2.00 dl/g and less than 2.50 dl/g, and comprises isophthalic acid in a content range of 0.1 to 2.0 mol%.

Description

Recycled fiber, vehicle material and manufacturing method thereof

FIELD OF THE INVENTION The present invention relates to recycled fibers, vehicle materials and manufacturing methods thereof.

Polyethylene terephthalate (hereinafter referred to as PET) is widely used as a vehicle material. For example, fabrics used in vehicle seat belts or air bags are made from PET yarn.

On the other hand, developed countries such as Europe are making it mandatory to use recycled materials for vehicle products such as seat belts and airbags while strengthening environmental regulations. Accordingly, a method of recycling waste PET discarded after being used as containers or fibers for manufacturing vehicle products is being considered.

Therefore, there is a need for a technology that is eco-friendly like the use of recycled PET and that can resolve concerns about deterioration in physical properties due to reuse of waste PET containing impurities.

One object of the present application is to provide an eco-friendly recycled fiber.

Another object of the present application is to provide a recycled PET fiber, which can have the same level of physical properties as a product using only virgin PET (PET).

Another object of the present application is to provide a vehicle material including recycled PET.

Another object of the present application is to provide a seat belt or air bag for a vehicle including the vehicle material.

The above object and other objects can all be solved by the present application described below.

The present application relates to a recycled fiber, an eco-friendly vehicle material, and a manufacturing method thereof. The eco-friendly vehicle material includes recycled fibers.

In this regard, the inventors of the present application described the components and viscosity of recycled PET used in manufacturing fibers, even when using recycled fibers including recycled PET for vehicle seat belts or airbag fabrics. It was confirmed that by appropriately controlling the , content and/or process, a vehicle material having physical properties equivalent to that of using raw PET can be provided.

In particular, it has been experimentally confirmed that, when yarn is manufactured using recycled PET described below, the properties of yarn (fiber) commercially required in the field of vehicle seat belts or air bags can be satisfied. became Specifically, in the case of a yarn used for a vehicle material, it is required to have a tensile strength of 5.0 gf/d or more and a cut elongation of 10% or more. It can show higher values than tensile strength and breaking elongation. Tensile strength and elongation at break are measured according to ASTM D 885 method.

In the present application, the term "recycled polyethyleneterephthalate (PET)" is used in the meaning of encompassing PET resin or recycled PET chips containing the PET resin that was first used for a specific purpose, such as containers, fibers, and tire cords, and wasted for recycling purposes. can Recycled PET may be referred to as r-PET.

In the present application, "virgin polyethyleneterephthalate (PET)" is to be distinguished from the recycled PET (or r-PET), and may refer to a PET resin that is not recycled or recycled or a PET chip including the same. Raw PET may be referred to as v-PET or generic PET.

In the present application, "regenerated fiber" may include recycled PET, that is, a PET component forming a fiber (yarn), and may include at least a recycled PET component.

In the present application, "vehicle material" may mean a fabric that can be used for a vehicle product or an article including the fabric. Specifically, the fabric may mean a fabric or nonwoven fabric used in an airbag or seat belt used in a vehicle.

In addition, unless otherwise specifically stated, in the present application, "including" refers to including any component (or component) without particular limitation, and is not construed as excluding the addition of other components (or components). does not

Hereinafter, the present invention will be described in more detail.

In one example relating to the present application, the present application relates to regenerated fibers. The regenerated fibers include regenerated PET.

The manufacturing method of the recycled PET used for forming the recycled fiber of the present application is not particularly limited. For example, recycled PET may be manufactured using a physical recycling method or a chemical recycling method known in the related art. Specifically, the physical recycling method may exemplify a method of recovering PET in the form of chips, flakes, and pellets through pulverization and washing, and the chemical recycling method is a method of recovering PET through a chemical reaction. A method of recovering raw materials is exemplified.

The regenerated fiber contains isophthalic acid or a unit derived therefrom in an amount of 0.1 to 2.0 mol%. Specifically, the isophthalic acid or a unit derived therefrom may be included in the recycled PET. In the case of melt spinning for yarn formation, it is preceded by melting the PET chip at a temperature higher than the melting point. Since the melting point temperature also increases when the crystallinity is high, the related process temperature must be increased. This increase in process temperature causes not only cost increase such as energy increase or facility improvement, but also thermal decomposition of PET and consequent deterioration of yarn properties. In addition, in the case of recycled PET, since the process of melting waste PET to recover the recycled PET in the form of chips, etc., the thermal decomposition of PET and the deterioration of the physical properties of the yarn are aggravated in the use of recycled PET. . In this regard, the isophthalic acid included to satisfy the above content range may lower the crystallinity of the recycled PET to an appropriate level, and as a result, the above-described problem may be prevented.

In one example, the lower limit of the content of isophthalic acid is 0.3 mol% or more, 0.4 mol% or more, 0.5 mol% or more, 0.6 mol% or more, 0.7 mol% or more, 0.8 mol% or more, 0.9 mol% or more, or 1.0 mol% % or more, and the upper limit thereof may be 1.8 mol% or less, 1.6 mol% or less, 1.4 mol% or less, 1.2 mol% or less, or 1.0 mol% or less.

In addition, the recycled PET may have an intrinsic viscosity of greater than 2.00 dl/g and less than 2.50 dl/g. As can be seen through the experimental examples below, when the intrinsic viscosity of the recycled PET is less than 2.00 dl/g, tensile strength and elongation at cut that are superior to commercial requirements cannot be obtained, and the intrinsic viscosity of the recycled PET is 2.50 dl/g or more. In some cases, there is a problem that spinning or sacrificing is impossible.

For example, the lower limit of the intrinsic viscosity of the recycled PET is 2.10 dl/g or more, 2.15 dl/g or more, 2.20 dl/g or more, 2.25 dl/g or more, 2.30 dl/g or more, 2.35 dl/g or more, 2.40 dl or more. /g or more or 2.45 dl/g or more. And, the upper limit may be, for example, 2.49 dl/g or less, 2.48 dl/g or less, 2.47 dl/g or less, 2.46 dl/g or less, or 2.45 dl/g or less, and more specifically, 2.40 dl/g or less. , 2.35 dl/g or less, 2.30 dl/g or less, or 2.25 dl/g or less.

In one example, the regenerated fiber may include 25 wt% to 95 wt% of regenerated PET as a PET component. When recycled PET having the above-described viscosity is used within this range, it is advantageous to secure higher tensile strength and cut elongation than the commercial level described above.

In one example, in the case where recycled PET is used to form recycled fibers in the above content, that is, in the weight % range, the content of isophthalic acid in the recycled PET may be calculated according to the content of recycled PET used in the recycled fibers. have. For example, if recycled PET and raw PET form regenerated fibers in content ratios of 50 wt% and 50 wt%, and the content of isophthalic acid contained in the regenerated fiber is 1 mol%, only recycled PET contains isophthalic acid In this case, it can be said that the content of isophthalic acid actually contained in recycled PET is 2 mol%.

In one example, the regenerated fiber may be formed of regenerated PET. Specifically, the regenerated fiber may be a fiber manufactured by melt spinning a material containing regenerated PET chips.

In another example, the regenerated fiber may further include raw PET. That is, the regenerated fiber may include regenerated PET and raw PET. For example, the regenerated fiber may be a fiber manufactured by melt-spinning regenerated PET and raw PET together. Specifically, the lower limit of the content of the regenerated PET component among the PET components melt-spun for manufacturing the regenerated fiber is, for example, 25% by weight or more, 30% by weight or more, 35% by weight or more, 40% by weight or more, 45 at least 50 wt%, at least 55 wt%, at least 60 wt%, at least 65 wt%, at least 70 wt%, at least 75 wt%, at least 80 wt%, at least 85 wt%, or at least 90 wt%; The upper limit thereof is, for example, less than 95% by weight, specifically 90% by weight or less, 85% by weight or less, 80% by weight or less, 75% by weight or less, 70% by weight or less, 65% by weight or less, 60% by weight or less. , 55 wt% or less, 50 wt% or less, 45 wt% or less, 40 wt% or less, 35 wt% or less, or 30 wt% or less. In addition, the upper limit of the content of the raw PET component among the PET components melt-spun for the production of regenerated fibers is, for example, 75% by weight or less, 70% by weight or less, 65% by weight or less, 60% by weight or less, 55% by weight or less. % or less, 50% or less, 45% or less, 40% or less, 35% or less, 30% or less, 25% or less, 20% or less, 15% or less, or 10% or less, and The lower limit is, for example, 5 wt% or more, 10 wt% or more, 15 wt% or more, 20 wt% or more, 25 wt% or more, 30 wt% or more, 35 wt% or more, 40 wt% or more, 45 wt% or more , 50 wt% or more, 55 wt% or more, 60 wt% or more, 65 wt% or more, or 70 wt% or more.

In one example, raw PET used with a recycled PET component comprising isophthalic acid may not contain isophthalic acid or units derived therefrom.

In one example, the intrinsic viscosity of the recycled PET may be greater than the intrinsic viscosity of the original PET. Since the viscosity and the molecular weight are generally proportional, the higher the viscosity of the recycled PET, the higher the molecular weight increases, so that improvement in physical properties can be expected. The inventor of the present application found that even if there are factors that degrade the properties of recycled PET, such as impurities or thermal decomposition during remelting, when the viscosity of recycled PET is higher than that of original PET, the yarn is more than commercially required for vehicle materials. It was confirmed that the physical properties can be sufficiently secured.

In one example, the raw PET may have an intrinsic viscosity in the range of 0.70 to 1.30 dl/g. Specifically, the lower limit of the intrinsic viscosity of the raw PET is, for example, 0.80 dl/g or more, 0.85 dl/g or more, 0.90 dl/g or more, 0.95 dl/g or more, 1.00 dl/g or more, 1.05 dl/g or more. , 1.10 dl/g or more or 1.15 dl/g or more, and the upper limit thereof is, for example, 1.25 dl/g or less, 1.20 dl/g or less, 1.15 dl/g or less, 1.10 dl/g or less, 1.05 dl/g or less. or less, 1.00 dl/g or less, 0.95 dl/g or less, 0.90 dl/g or less, or 0.85 dl/g or less.

In one example, the regenerated fiber comprises recycled PET having an intrinsic viscosity of greater than 2.00 dl/g and less than 2.50 dl/g; and raw PET having an intrinsic viscosity in the range of 0.80 to 1.20 dl/g. Specifically, in the case of recycled PET, physical and/or chemical treatment is performed to remove impurities, but the physical properties (eg, strength or elongation, etc.) of the yarn obtained after spinning may be lowered because there are still many impurities compared to original PET. . In addition, in order to manufacture recycled PET in the form of chips, an additional melting process is also required, and thermal decomposition of PET generated in this process is also one of the causes of deterioration of the physical properties of the yarn. The inventor of the present application has found that when the intrinsic viscosity of the original PET and the recycled PET respectively satisfy the above ranges, despite the above-described cause of the deterioration of the physical properties of the yarn, it is environmentally friendly and better than when only recycled PET is used. In addition, it was confirmed that the yarn physical properties above the commercially required values can be sufficiently secured. Specifically, the intrinsic viscosity of the regenerated PET is, for example, the lower limit thereof is 2.10 dl/g or more, 2.15 dl/g or more, 2.20 dl/g or more, 2.25 dl/g or more, 2.30 dl/g or more, 2.35 dl/g. g or more, 2.40 dl/g or more, or 2.45 dl/g or more. In addition, the upper limit of the intrinsic viscosity of the recycled PET may be, for example, 2.49 dl/g or less, 2.48 dl/g or less, 2.47 dl/g or less, 2.46 dl/g or less, or 2.45 dl/g or less, and more specifically, It may be 2.40 dl/g or less, 2.35 dl/g or less, 2.30 dl/g or less, or 2.25 dl/g or less.

In one example, the regenerated fiber comprises 25% to 60% by weight of recycled PET having an intrinsic viscosity of greater than 2.00 dl/g and less than 2.50 dl/g; and 40 to 75 wt% of raw PET having an intrinsic viscosity in the range of 0.80 to 1.20 dl/g. The inventor of the present application found that when the intrinsic viscosity and content of raw PET and recycled PET used for manufacturing recycled fibers satisfy the above numerical ranges, despite factors that degrade properties of recycled PET, such as impurities or thermal decomposition during remelting, And it was confirmed that the yarn properties beyond those commercially required can be sufficiently secured. In this case, the intrinsic viscosity of the regenerated PET is, for example, the lower limit thereof is 2.10 dl/g or more, 2.15 dl/g or more, 2.20 dl/g or more, 2.25 dl/g or more, 2.30 dl/g or more, 2.35 dl/g or more. or more, 2.40 dl/g or more, or 2.45 dl/g or more. In addition, the upper limit of the intrinsic viscosity of the recycled PET may be, for example, 2.49 dl/g or less, 2.48 dl/g or less, 2.47 dl/g or less, 2.46 dl/g or less, or 2.45 dl/g or less, and more specifically, It may be 2.40 dl/g or less, 2.35 dl/g or less, 2.30 dl/g or less, or 2.25 dl/g or less. In addition, the content of the recycled PET may be, for example, a lower limit of 30% by weight or more, 35% by weight or more, 40% by weight or more, 45% by weight or more, 50% by weight or more, or 55% by weight or more, and the upper limit thereof may be 60 wt% or less, 55 wt% or less, 50 wt% or less, 45 wt% or less, 40 wt% or less, or 35 wt% or less.

The regenerated fiber may have a fineness of a predetermined value at a level that satisfies the properties of the commercially required yarns (fibers) described above. For example, the single yarn fineness of the regenerated fiber may be in the range of 2 to 15 denier. In addition, the regenerated fibers may have a total fineness in the range of 400 to 2,000 denier. Although not particularly limited, the single yarn fineness may be measured by taking the yarn to a length of 9,000 m using a bobbin, measuring the weight, obtaining the total fineness of the yarn, and dividing the yarn by the number of filaments.

When the components, content and/or viscosity of the regenerated PET described above, and the content and/or viscosity of v-PET are adjusted, the tensile strength and cut elongation of the regenerated fiber can be more precisely controlled.

The tensile strength of the regenerated fiber is higher than the 5.0 gf/d level required for the aforementioned fiber material for vehicles. Specifically, the lower limit of the tensile strength of the regenerated fiber is, for example, 7.0 gf/d or more, 7.5 gf/d or more, 8.0 gf/d or more, 8.5 gf/d or more, 9.0 gf/d or more, 9.5 gf/d or more. or more or 10.0 gf/d or more. In addition, the upper limit of the tensile strength of the regenerated fiber is not particularly limited, but for example, 15.0 gf/d or less, 14.5 gf/d or less, 14.0 gf/d or less, 13.5 gf/d or less, 13.0 gf/d or less, 12.5 gf/d or less. gf/d or less, 12.0 gf/d or less, 11.5 gf/d or less, 11.0 gf/d or less, 10.5 gf/d or less, or 10.0 gf/d or less.

The cut elongation of the regenerated fiber is superior to the 10% level required for the aforementioned fiber material for vehicles. Specifically, the cut elongation lower limit of the regenerated fiber is, for example, 13.0% or more, 13.5% or more, 14.0% or more, 14.5% or more, 15.0% or more, 15.5% or more, 16.0% or more, 16.5% or more, 17.0% or more. or more, 17.5% or more, 18.0% or more, 18.5% or more, 19.0% or more, 19.5% or more, or 20.0% or more. In addition, the upper limit of the cut elongation of the regenerated fiber is not particularly limited, but for example, 25.0% or less, 24.5% or less, 24.0% or less, 23.5% or less, 23.0% or less, 22.5% or less, 22.0% or less, 21.5% or less , 21.0% or less, 20.5% or less, 20.0% or less, 19.5% or less, or 19.0% or less.

In another example related to the present application, the present application relates to a method of making a regenerated fiber.

The method comprises melt spinning a material comprising recycled PET comprising isophthalic acid in a content range of 0.1 to 2.0 mol% and having an intrinsic viscosity of greater than 2.00 dl/g and less than 2.50 dl/g. An undrawn yarn is produced by melt spinning.

The shape of the recycled PET contained in the material is not particularly limited. For example, it may be in the form of a chip.

Properties related to the recycled PET and its content are the same as described above.

In one example, the material may further comprise raw PET. Specifically, the method comprises: recycled PET containing isophthalic acid in a content range of 0.1 to 2.0 mol% and having an intrinsic viscosity of greater than 2.00 dl/g and less than 2.50 dl/g; and melt spinning a material comprising raw PET.

The shape of the raw PET contained in the material is not particularly limited. For example, it may be in the form of a chip.

The characteristics or content related to the raw PET are the same as described above.

In one example, the melting temperature for the material may be at least 250 °C. Specifically, the lower limit of the melting temperature may be, for example, 260 ° C. or higher, 270 ° C. or higher, 280 ° C. or higher, 290 ° C. or higher, or 300 ° C. or higher, and the upper limit is, for example, 315 ° C. or lower, 310 ° C. or lower. , 300 °C or lower, 290 °C or lower, or 280 °C or lower. When melting is performed within the above range, sufficient melting and excellent spinnability can be ensured, and excessive thermal decomposition of PET can be prevented.

In one example, the spinning may be performed in a speed range of about 250 to 4,000 m/min.

In the case of a spinneret used for melt spinning, an appropriately designed one at a level that can obtain the desired properties of the regenerated fiber may be used. Although not particularly limited, a spinneret designed so that the single yarn fineness of the regenerated fiber may range from 2 to 15 denier may be used.

In one example, cooling may be applied to melt spun PET. The cooling method is not particularly limited. For example, cooling may be performed using wind at a temperature of 15 to 60 °C.

In one example, the stretching process for the polyester undrawn yarn may be made. Equipment including a plurality of rollers may be used for stretching, but the equipment used is not particularly limited.

In one example, the stretching may be performed at a level in which the total stretching ratio is in the range of about 4.5 to 6.0. That is, the method may further include a stretching step of stretching the undrawn yarn prepared after melt spinning to satisfy a total draw ratio of 4.5 to 6.0. When the total draw ratio exceeds 6.0, there is a problem such as cutting due to overstretching. In addition, when the total draw ratio is less than 4.5, the degree of orientation of the fibers may be low, and thus the strength of the yarn may be lowered.

After the stretching, heat setting, relaxation and winding processes may be further performed. These processes can be suitably performed using well-known equipment.

In one example, the relaxation rate may be adjusted in the range of 1 to 3%. That is, the method may further include a relaxation step in the range of 1 to 3% of the relaxation rate after the stretching. If the relaxation rate is less than 1%, the yarn may be cut because the tension is applied too high, and if it exceeds 3%, the airtightness or durability may be poor.

Specific characteristics or configuration of the regenerated fiber manufactured through the above method are the same as described above.

In another example related to the present application, the present application relates to an eco-friendly vehicle material including a recycled fiber.

The specific characteristics or composition of the recycled fiber used in the eco-friendly vehicle material is the same as described above.

The eco-friendly vehicle material may be, for example, a fabric used for vehicle airbags or seat belts.

In one example, the fabric may be manufactured through beaming, weaving, refining, and tentering processes using the above-described regenerated fiber yarns as weft and warp yarns. The fabric may be manufactured using a conventional weaving machine, and is not limited to using any specific loom. However, plain weave fabrics can be manufactured using Rapier Looms, Air Jet Looms, Water Jet Looms, etc. Loom) can be used.

In one example, the fabric for the airbag may be a plain weave having a fabric density of 40 x 40 to 55 x 55 per inch in warp and weft directions. When the above range is satisfied, it is advantageous to satisfy airtightness and strength required for an airbag.

In one example, the fabric for the airbag may satisfy a stiffness of 20 N or less measured according to ASTM D 4032. When the stiffness exceeds the above range, the higher the stiffness, the stiffer the fabric for the airbag, so the foldability and storage properties of the airbag cushion are not good. Also, when the airbag is inflated due to an impact, the user's body may be injured.

In one example, the fabric for the seat belt may be manufactured to have a weaving density of 280 yarns/inch or less in consideration of weight or fit. Specifically, the warp density may be 230 to 280 bones/inch, or preferably 240 to 270 bones/inch. If it is more than 230 bones/inch, it is advantageous to safely support passengers in the event of a vehicle collision. In addition, in consideration of the drivability when the seat belt is detached, the weft density of the fabric for the seat belt may be, for example, 4 yarns/inch or more. In addition, the upper limit of the weft density of the seat belt fabric may be, for example, 8 yarns/inch or less when preventing excessive increase in the thickness of the seat belt and considering the fit of the passenger.

In one example, the fabric for the seat belt may satisfy at least a 4th grade in friction fastness measured according to KS K 0650-1. Therefore, the fabric for a seat belt of the present application has excellent properties in which the dye does not come off even when friction with the user's clothes occurs.

According to one embodiment of the present invention, since it is manufactured using recycled PET, it is possible to provide a recycled fiber that is environmentally friendly and satisfies the properties of yarn (fiber) more than commercially required. In addition, such regenerated fibers may be used as fabrics for vehicle seat belts or air bags.

Hereinafter, the action and effect of the invention will be described in more detail through specific examples of the invention. However, the embodiment is merely an example of the invention, and the scope of the invention is not limited thereto in any sense.

Examples and Comparative Examples

Example 1

As shown in Table 1, the polyester undrawn yarn was prepared by melt spinning and cooling an r-PET chip containing 0.8 mol% of IPA and having an intrinsic viscosity of 2.20 dl/g, followed by stretching and relaxation processes. A polyester yarn, that is, a regenerated fiber (single yarn fineness of about 7 denier) was prepared. At this time, the spinning temperature for the melt spinning process was adjusted to about 290 °C, the total draw ratio to about 5.0, and the relaxation rate to about 1.5%.

Example 2, and Comparative Examples 1-2

As shown in Table 1 or Table 2, components, content and/or viscosity of r-PET, and content and/or viscosity of v-PET were adjusted. And, in the same manner as in Example 1, after preparing undrawn polyester yarn by cooling the r-PET chip and v-PET chip after melt spinning, the undrawn yarn is drawn at the same draw ratio and heat treatment is performed to heat the polyester yarn, That is, a regenerated fiber was prepared.

The composition of the yarn used in Examples and Comparative Examples is described in Tables 1 and 2, respectively.

Metrics

1. Content of IPA (isophthalic acid) in regenerated fiber

The PET fibers prepared in Examples and Comparative Examples were dissolved in Trifluoroacetic Acid-d (System Peak: 11.50) as a solvent at a concentration of 2 to 3% to prepare a sample, and IPA in the sample using Oxford's AS400 (64 MHz) equipment The content of was measured.

(1) IPA Peak: (a) 8.7~8.8ppm, (b) 8.2~8.3ppm, (c) 7.5~7.6ppm

(2) IPA content measurement method

H-NMR of 64 MHz was measured using the prepared sample, and it was calculated using Equation 1 below.

<Equation 1>

IPA content (mol%) = (area a + area b + area c) X 100 (%) / total area

2. Intrinsic Viscosity of r-PTE and v-PET

The intrinsic viscosity of the r-PTE chip and the v-PET chip was measured, respectively. Specifically, the emulsion is extracted from the sample using carbon tetrachloride, dissolved in OCP (Ortho Chloro Phenol) at 160±2℃, and then the sample in the viscosity tube is used at 25℃ using an automatic viscometer (Skyvis-4000). The viscosity was measured. And intrinsic viscosity (I.V.) was obtained according to the calculation of the following procedure.

Intrinsic Viscosity (I.V.) = {(0.0242 X Rel)+0.2634} X F

Rel = number of seconds of solution X specific gravity of solution X viscosity coefficient / OCP viscosity

F = (I.V. of standard chip) / (average I.V. of three measured standard chip with standard copper length)

3. Tensile strength of yarn (unit: gf/d) and elongation at break (unit: %)

The tensile strength and cut elongation of the yarn were measured according to ASTM D 885 standard.

4. Fastness to friction

(1) Manufacturing of seat belt fabric

A semi-finished seat belt product having a weft density of 7.1 yarns/inch, warp density of 270 yarns/inch and a width of 49 mm was manufactured by weaving the fiber yarns prepared in Examples and Comparative Examples at 270 yarns. Then, the seat belt sample was dyed using S-Type black disperse dye. Friction fastness was measured for the dyed samples. Through this, it is possible to check the degree to which the dye is separated by friction with the clothes.

(2) Friction fastness of fabric

The color fastness to friction was measured according to KS K 0650-1 (chronometer method). The detailed measurement process is as follows.

1) Scope of application: application of dyes

2) Requested sample size: 20 cm x 20 cm

3) test piece

-Clothes: 2 pieces of 20 cm x 10 cm rectangle

-Thread: Prepared by knitting to form a 20 cm x 10 cm rectangle or winding lengthwise on thick paper.

4) Test method

- Leave the test piece and dry rubbing cloth in standard condition for 4 hours

- For wet friction test, wet the dry friction cotton cloth with distilled water at room temperature before testing and prepare it in a 100% wet state.

- After applying a load of 900 g, tightly wrap each of the friction elements with dry and wet cotton cloth, and then rub 10 cm between the specimens for 10 seconds in a 10 second pattern. At this time, in principle, the test is carried out on the surface, and in the case of fabrics of various colors, all colors are arranged in one direction of the test piece (if the color area is large enough to rub, divide the test piece by color and proceed with the test)

5) Check result

Record the water supply after judgment by comparing it with the standard gray table for contamination of the specimen (wet water supply)

5. Stiffness (Unit: N)

(1) Manufacture of fabric for airbags

After weaving the fabric with a plain weave having a fabric density of 46 x 46 per inch in the warp and weft directions, the stiffness was measured.

(2) Measurement of stiffness

The stiffness of the fabric was measured by the Circular Bend method using a stiffness measuring device according to ASTM D 4032 of the American Society for Testing and Materials. The degree of flexibility of the fabric for airbags can be compared through the lecture diagram.

The results measured for Examples and Comparative Examples are shown in Tables 1 and 2, respectively.

Example v-PET
viscosity of
(dl/g) Viscosity of r-PET
(dl/g) PET content
(weight%)
(v-PET
:
r-PET)
in r-PET
IPA content (mol%) The tensile strength
(gf/d) amputee
(%) Seat-belt related friction fastness
(wet water) Airbag related lectures (N) One 1.0±0.2 2.2 50:50 0.8 9.6 18.5 4 15 2 1.0±0.2 2.2 70:30 0.4 10.1 19.1 4 15

comparative example v-PET
viscosity of Viscosity of r-PET PET content
(weight%)
(v-PET
:
r-PET)
in r-PET
IPA content (mol%) The tensile strength
(gf/d) amputee
(%) Seat-belt related friction fastness
(wet water) Airbag related lectures (N) One 1.0±0.2 2.2 0:100 1.5 Non-radiation (not measurable) no radiation
(not measurable) - - 2 1.0±0.2 2.5 70:30 0.4 Non-radiation (not measurable) no radiation
(not measurable) - -

Claims (16)

Recycled polyethylene terephthalate (PET) having an intrinsic viscosity of more than 2.00 dl/g and less than 2.50 dl/g is included in the range of 25 wt% to 95 wt%,
A regenerated fiber comprising isophthalic acid in a content range of 0.1 to 2.0 mole %. The regenerated fiber of claim 1 , wherein the regenerated PET comprises the isophthalic acid. The regenerated fiber of claim 1 , wherein the regenerated fiber has a tensile strength of 5.0 gf/d or greater and an elongation at break of 10% or greater. The regenerated fiber of claim 1 , further comprising virgin polyethyleneterephthalate (PET). 5. The regenerated fiber of claim 4, wherein the intrinsic viscosity of the raw PET is less than that of the regenerated PET. 6. The regenerated fiber of claim 5, wherein the raw PET has an intrinsic viscosity in the range of 0.70 to 1.30 dl/g. 5. The recycled PET according to claim 4, wherein the intrinsic viscosity is greater than 2.00 dl/g and less than 2.50 dl/g; and raw PET having an intrinsic viscosity in the range of 0.80 to 1.20 dl/g. 8. The composition according to claim 7, comprising: 25% to 60% by weight of recycled PET having an intrinsic viscosity of greater than 2.00 dl/g and less than 2.50 dl/g; and 40 to 75% by weight of raw PET having an intrinsic viscosity in the range of 0.80 to 1.20 dl/g. A method for producing a recycled fiber, comprising melt spinning a material comprising isophthalic acid in a content range of 0.1 to 2.0 mol% and comprising recycled PET having an intrinsic viscosity of greater than 2.00 dl/g and less than 2.50 dl/g. 10. The method of claim 9, wherein the material further comprises raw PET. The method of claim 9, wherein the melt temperature in the melt spinning is 250° C. or higher. 10. The method of claim 9, further comprising a drawing step of drawing the undrawn yarn prepared after the melt spinning to satisfy a total draw ratio of 4.5 to 6.0. 13. The method of claim 12, further comprising a relaxation step in the range of 1 to 3% of the relaxation rate after the stretching, the regenerated fiber manufacturing method. An eco-friendly vehicle material, which is a fabric or non-woven fabric comprising the recycled fiber according to claim 1 . The eco-friendly vehicle material according to claim 14, wherein the stiffness measured according to ASTM D 4032 is 20 N or less. The eco-friendly vehicle material according to claim 14, wherein the friction fastness measured according to KS K 0650-1 satisfies the 4th grade.