Infrared absorbing polyester yarn with high strength and method of preparing the same, and safety belt

Abstract

This invention relates to high-strength infrared-absorbing polyester yarn and its preparation method, and more specifically, to high-strength infrared-absorbing polyester yarn that, when used in industrial strip fabrics, safety belts, ropes, fabrics, etc., exhibits characteristics different from ordinary yarns when photographed with an infrared camera due to its infrared absorption properties.

Description

Technical Field

[0001] This invention relates to high-strength infrared-absorbing polyester yarn and its preparation method, and more specifically, to high-strength infrared-absorbing polyester yarn that, when used in industrial ribbon fabrics, ropes, fabrics, etc., exhibits characteristics different from ordinary yarns when photographed with an infrared camera due to its infrared absorption properties. Prior Technology

[0002] Polyester yarns, represented by polyethylene terephthalate (PET), are widely used in fiber, film, and resin applications due to their excellent mechanical strength and chemical resistance. For example, in the case of fibers, they are used not only in clothing but also extensively as reinforcing materials for rubber products such as tire cords, seat belts, and webbing. Among these industrial polyester fibers, high-strength polyester fibers with polyethylene terephthalate as the main component are now widely used in seat belt yarns.

[0003] Typically, polyester fibers used in seat belts are dyed after being made into a strip fabric from yarn. However, this process reduces the strength due to high-temperature heat treatment. Technological development is focused on increasing the strength of the yarn using high-strength fibers.

[0004] The polyester yarns used in the aforementioned industries also frequently need to possess physical properties that vary depending on the product, including infrared absorption properties or electromagnetic wave shielding properties.

[0005] Infrared-absorbing polyester yarns mainly include those containing phthalocyanine, phthalocyanine, squarylium compound, diammonium, nitrosyl, anthocyanin, aniline black, triphenylmethane, or metal oxides such as tungsten oxide. However, while the aforementioned existing infrared-absorbing polyester yarns can be used as clothing materials, their low strength (less than 6.0 g / d) makes them unsuitable for applications requiring high strength, such as ropes, seat belts, and ribbon fabrics.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: KR 10-1306579 B

[0009] Patent Document 2: KR 2022-0146563 A

[0010] Patent Document 3: KR ​​2012-0133035 A Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] The purpose of this invention is to provide a high-strength infrared-absorbing polyester yarn that contains a functional substance that exhibits infrared absorption properties without reducing its strength, and a method for preparing the same.

[0013] Technical means to solve the problem

[0014] One embodiment of the present invention for solving the above-mentioned problems relates to a high-strength infrared-absorbing polyester yarn comprising a carbon-based infrared absorber that absorbs light in the near-infrared region with wavelengths from 750 nm to 3000 nm, and is composed of polyethylene terephthalate with an intrinsic viscosity (IV) of 0.7 dl / g to 1.0 dl / g and an strength of 8.0 g / d or more.

[0015] The carbon-based infrared absorber can be carbon black, graphite, carbon nanotubes, or carbon nanofibers.

[0016] The carbon black may be carbon black with a particle size of 10 nm to 50 nm and a specific surface area (total surface area of ​​carbon black particles per unit mass) of 90 m² / g to 110 m² / g.

[0017] The carbon nanotubes can be single-walled carbon nanotubes (SWNTs), multi-walled carbon nanotubes (MWNTs), or composites thereof, and the carbon nanotubes can have a diameter of 1 nm to 50 nm. The content of the carbon-based infrared absorber can be 30 ppm to 10,000 ppm based on the total weight of the high-strength infrared-absorbing polyester yarn.

[0018] Another embodiment of the present invention for solving the above-mentioned problems relates to a method for preparing a high-strength infrared-absorbing polyester yarn, comprising: a step of preparing a polymer by mixing and melting a polyethylene terephthalate masterbatch containing a carbon-based infrared absorber having an intrinsic viscosity (IV) of 0.7 dl / g to 1.0 dl / g and polyethylene terephthalate chips having an intrinsic viscosity (IV) of 1.0 dl / g to 1.2 dl / g; and a step of obtaining polyester yarn by spinning the polymer.

[0019] Another embodiment of the present invention for solving the above problems relates to a safety belt comprising the high-strength infrared-absorbing polyester yarn of the present invention.

[0020] Compared with the efficacy of previous technologies

[0021] The high-strength infrared-absorbing polyester yarn of the present invention provides the following advantages: the reflectivity at a wavelength of 950nm is ensured to be below 70%, the strength is above 8.0g / d, and the appearance quality is good.

[0022] The yarn of the present invention has the following characteristics: unlike ordinary yarn which appears white in an infrared camera, it appears dark gray to black in an infrared camera by absorbing light in the infrared region, thus distinguishing it from ordinary yarn.

[0023] When using the polyester yarn of the present invention, high strength can be maintained by reducing the strength reduction in the processing steps, the number of warp yarns in the fabric for seat belts can be reduced, thereby reducing the thickness or width of the seat belt, and obtaining a seat belt that is both high-strength and lightweight at low cost. Simple Explanation of the Diagram

[0024] Figure 1 is a photograph taken using an infrared camera of the polyester yarns prepared in Example 1 and Comparative Example 2 of the present invention. Implementation

[0025] The present invention will now be described in more detail with reference to the accompanying drawings.

[0026] In describing this invention, to avoid obscuring the essence of the invention, specific descriptions of relevant well-known functions or structures will be omitted.

[0027] In this application, terms such as “comprising” or “having” indicate the presence of features, figures, steps, operations, structural elements, accessories, or combinations thereof described in the specification, and should not be construed as precluding the existence or additional possibilities of more than one other feature, figure, step, operation, structural element, accessory, or combination thereof.

[0028] When indicating the allowable error in the preparation and substances inherent in the meaning mentioned, the terms "about," "substantially," etc., used in this specification to indicate the degree are used in the sense of the value or close to the value.

[0029] One embodiment of the present invention relates to a high-strength infrared-absorbing polyester yarn comprising a carbon-based infrared absorber that absorbs light in the near-infrared region with wavelengths from 750 nm to 3000 nm, and is composed of polyethylene terephthalate with an intrinsic viscosity (IV) of 0.7 dl / g to 1.0 dl / g and an strength of 8.0 g / d or more.

[0030] The carbon-based infrared absorber can be carbon black, graphite, carbon nanotubes, or carbon nanofibers.

[0031] The carbon black may be carbon black with a particle size of 10 nm to 50 nm and a specific surface area of ​​90 m² / g to 110 m² / g.

[0032] The carbon nanotubes can be single-walled carbon nanotubes, multi-walled carbon nanotubes, or composites thereof, and the diameter of the carbon nanotubes can be from 1 nm to 50 nm.

[0033] Preferably, the content of the carbon-based infrared absorber can be from 30 ppm to 10,000 ppm, based on the total weight of the high-strength infrared-absorbing polyester yarn.

[0034] The reflectivity of the yarn at a wavelength of 950nm can be below 70%, below 60%, below 50%, below 40%, or below 30%.

[0035] In this invention, the yarn is evaluated based on a masterbatch concentration and dosage that ensures a reflectance of less than 70% at a wavelength of 950 nm. When the reflectance is less than 70% at a wavelength of 950 nm, it appears gray to black in an infrared camera, thus achieving an effect that distinguishes it from ordinary yarns that appear bright due to their lack of infrared absorption.

[0036] The tensile strength of the prepared polyester yarn can be 8.0~12 g / d, preferably 8.5~11.5 g / d, and more preferably 9.0~11 g / d. In this case, if the tensile strength of the polyester yarn is less than the range described above, the stability of the seatbelt strap fabric will be reduced; if it exceeds the range described above, productivity will be reduced.

[0037] Furthermore, the fineness of the polyester yarn can be 100-3000 denier, preferably 500-2000 denier, and more preferably 1000-1500 denier. Simultaneously, the fineness of the polyester yarn's monofilament can be 1-20 denier, preferably 5-15 denier, and more preferably 8-14 denier. In this case, if the fineness of the polyester yarn and the monofilament fineness are both less than the aforementioned ranges, the stability of the industrial fiber will be reduced; if they exceed the aforementioned ranges, the fabric will have a poor tactile feel.

[0038] Another embodiment of the present invention relates to a method for preparing a high-strength infrared-absorbing polyester yarn, comprising: a step of preparing a polymer by mixing and melting a polyethylene terephthalate masterbatch containing a carbon-based infrared absorber having an intrinsic viscosity (IV) of 0.7 dl / g to 1.0 dl / g and polyethylene terephthalate chips having an intrinsic viscosity (IV) of 1.0 dl / g to 1.2 dl / g; and a step of obtaining polyester yarn by spinning the polymer.

[0039] First, a polyethylene terephthalate masterbatch containing pigments with the property of absorbing light in the 750-3000 nm wavelength range, which is the near-infrared region, is prepared. In this invention, if the polyethylene terephthalate is to be used in the melt spinning process, an infrared absorber with the following characteristics is used: it is not thermally decomposed at around 300°C, and exhibits performance exceeding specified limits due to minimal photodecomposition when exposed to sunlight for extended periods. In this invention, the carbon-based infrared absorber can be carbon black, graphite, carbon nanotubes, or carbon nanofibers. The carbon black can have a particle size of 10 nm to 50 nm and a specific surface area of ​​90 m² / g to 110 m² / g. The carbon nanotubes can be single-walled carbon nanotubes, multi-walled carbon nanotubes, or composites thereof, and the diameter of the carbon nanotubes can be 1 nm to 50 nm.

[0040] In this invention, the infrared absorber, i.e., the infrared absorbing particles, can have an average particle size of 1-50 nm, but is not limited to this. If the average particle size of the infrared absorbing particles is less than 1 nm, the yield will be reduced during the preparation of the masterbatch due to low dispersibility, and the prepared polyester yarn will also have uneven color due to uneven dispersion. Furthermore, if the average particle size of the infrared absorbing particles is greater than 50 nm, many broken fibers will occur during the preparation of the polyester yarn.

[0041] Preferably, the content of the carbon-based infrared absorber can be from 30 ppm to 10,000 ppm, based on the total weight of the high-strength infrared-absorbing polyester yarn.

[0042] The appropriate amount of infrared absorber added to the yarn varies depending on the properties of the different types of infrared absorbers used. Based on the total weight of the yarn, the infrared absorber content can range from 30 ppm (corresponding to 750 ppm in the masterbatch) to 10,000 ppm (corresponding to 250,000 ppm in the masterbatch). If the infrared absorber content is less than 30 ppm, the desired properties cannot be obtained due to reduced infrared absorption. If the infrared absorber content is greater than 10,000 ppm, it is difficult to prepare masterbatch chips and ensure uniform dispersion.

[0043] In this invention, in order to prepare high-strength polyester yarn with a strength of 8.0 g / d or higher, polyethylene terephthalate masterbatch containing infrared absorber is solid-phase polymerized in a manner with an intrinsic viscosity (IV) of 0.70 dl / g to 1.0 dl / g.

[0044] If the intrinsic viscosity (IV) of the masterbatch is less than 0.7 dl / g, it is not conducive to expressing yarn strength. If the intrinsic viscosity (IV) of the masterbatch is greater than 1.0 dl / g, the uneven melting of the masterbatch will increase fluff, resulting in poor yarn appearance quality.

[0045] Preferably, the intrinsic viscosity (IV) of polyethylene terephthalate chips, which is the main material for preparing yarn, is 1.0 dl / g to 1.2 dl / g. If the intrinsic viscosity (IV) of polyethylene terephthalate chips is less than 1.0 dl / g, it is not conducive to the performance of yarn strength. If it is greater than 1.20 dl / g, the uneven melting of polyethylene terephthalate chips will increase the fluff, resulting in poor appearance quality of the yarn.

[0046] In order to adjust the intrinsic viscosity (IV) of the polyethylene terephthalate masterbatch containing the infrared absorber and the polyethylene terephthalate chips as the main material to the desired level, the materials were solid-state polymerized for use. The solid-state polymerization was carried out at a temperature of 120°C and a pressure of less than 1 torr. After surface crystallization at a temperature of 140°C, the temperature was raised to 235°C and held to carry out solid-state polymerization until the desired intrinsic viscosity (IV) was reached.

[0047] A molten polymer is prepared by mixing polyethylene terephthalate masterbatch containing an infrared absorber with adjusted intrinsic viscosity (IV) as described above with polyethylene terephthalate chips as the main material in an appropriate proportion. This molten polymer is then spun through a spinning nozzle and rapidly cooled and solidified by passing it through a cooling zone. In this case, a heating device of a specified length can be installed as needed, from the nozzle to the starting point of the cooling zone, i.e., within the length range of the protective cover. This zone is referred to as the delayed cooling zone or heating zone, and it has a length of 150 mm to 450 mm and a temperature of 320°C to 400°C (air contact surface temperature).

[0048] In the cooling zone, depending on the method of blowing cooling air, open quenching, circular closed quenching, radial outflow quenching, and radial inflow quenching can be used, but are not limited to these. In this case, the temperature of the cooling air injected into the cooling zone for quenching is adjusted to 20°C to 50°C. This quenching, utilizing the sharp temperature difference between the protective cover and the cooling zone, aims to increase the orientation of the undrawn filament and the formation of connecting chains between crystals by raising the curing point of the polymer in the spinning process and the spinning tension.

[0049] Then, during the cooling process, while reducing the coefficient of friction between the solidified spun yarn filaments, the spun yarn is oiled at a rate of 0.5% to 1.2% by weight using an oiling device employing an oiling agent with excellent stretchability and thermal efficiency. The oiled spun yarn is then spun to form an unstretched yarn. This unstretched yarn is then subjected to multi-stage stretching via stretching rollers and wound at a speed of 2500 m / min to 4500 m / min to prepare a high-strength infrared-absorbing polyester yarn with an infrared absorption strength of 8.0 g / d or higher.

[0050] When stretching unstretched yarn, the yarn passing through the first stretching roller can be stretched by a spin draw method through a series of stretching rollers to form yarn. In the stretching process, the unstretched yarn can be stretched in multiple stages, and the temperature of each stretching roller can be higher than the glass transition temperature of the unstretched yarn but lower than 95°C. Preferably, the temperature of the last stretching roller is 200°C to 250°C.

[0051] Furthermore, preferably, the total draw ratio of the formed yarn is 4.0 to 7.0. If the draw ratio is less than 4.0, productivity and yarn strength will be reduced. If the draw ratio is greater than 7.0, the workability of the yarn will be reduced and yarn breakage will occur due to the increased crystallization of the amorphous parts. The uniformity of the molecular chains will be reduced due to the breakage of the molecular chains in the amorphous parts of the yarn microstructure, which will reduce the strength utilization rate. Therefore, this is not preferred.

[0052] Another embodiment of the present invention relates to a strip fabric and a seat belt prepared using the high-strength infrared-absorbing polyester yarn of the present invention.

[0053] Using the high-strength infrared-absorbing polyester yarn of this invention as the warp and ordinary polyester yarn as the weft, a seatbelt strip fabric can be prepared. This invention reduces the number of warp yarns used in the textile process by increasing the yarn strength, thereby making the seatbelt strip fabric lighter. The strip fabric of this invention is effectively used as seatbelts, parachute straps and parachute lines, safety nets, trampolines, etc.

[0054] The present invention will now be described in detail through embodiments. However, these embodiments are only for illustrative purposes, and the scope of the present invention is not limited to these embodiments.

[0055] Example

[0056] Example 1

[0057] As an infrared absorber, polyethylene terephthalate (PET) masterbatch was prepared using carbon black at a concentration of 750 ppm, and then subjected to solid-state polymerization to obtain an intrinsic viscosity (IV) of 0.90 dl / g. PET chips, as the main material, were then subjected to solid-state polymerization to obtain an intrinsic viscosity (IV) of 1.05 dl / g for use. 96% of PET chips were mixed and melted with 4% of PET masterbatch containing the infrared absorber, and spun using a 72-hole nozzle to achieve a carbon black concentration of 30 ppm in the yarn. After a stretching process at a draw ratio of 5.7, a 1000 denier / 72 filament polyester yarn was prepared by winding at a speed of 3150 m / min. Figure 1 shows a photograph taken using an infrared (IR) camera of a seatbelt belt fabric manufactured using the polyester yarn of this invention. Referring to Figure 1, in the image of the seatbelt strip fabric of the present invention taken using an infrared camera, areas distinct from Comparative Example 1 can be identified. Referring to Figure 1, the yarn of the infrared-absorbing polyester yarn of Example 1 exhibits a deeper gray or even black color, which is distinct from the ordinary yarn of Comparative Example 1, which does not have infrared absorption properties, confirming an improved recognition effect.

[0058] Example 2

[0059] Except that the concentration of carbon black in the yarn was 5,000 ppm after preparing a polyethylene terephthalate masterbatch containing 125,000 ppm carbon black as an infrared absorber, polyester yarn was prepared in the same manner as in Example 1.

[0060] Example 3

[0061] Except for the preparation of a polyethylene terephthalate masterbatch containing 250,000 ppm carbon black as an infrared absorber, the concentration of carbon black in the yarn was 10,000 ppm, and the preparation of polyester yarn was carried out in the same manner as in Example 1.

[0062] Example 4

[0063] Except that the polyester yarn was prepared in the same manner as in Example 1, after preparing a polyethylene terephthalate masterbatch containing 750 ppm SWNT as an infrared absorber, the concentration of SWNT in the yarn was 30 ppm.

[0064] Example 5

[0065] Except that the concentration of SWNT in the yarn was 1,000 ppm after preparing a polyethylene terephthalate masterbatch containing 25,000 ppm SWNT as an infrared absorber, polyester yarn was prepared in the same manner as in Example 1.

[0066] Example 6

[0067] Except that the concentration of MWNT in the yarn was 30 ppm after preparing a polyethylene terephthalate masterbatch containing 750 ppm of MWNT as an infrared absorber, polyester yarn was prepared in the same manner as in Example 1.

[0068] Example 7

[0069] Except that the concentration of MWNT in the yarn was 400 ppm after preparing a polyethylene terephthalate masterbatch containing 10,000 ppm of MWNT as an infrared absorber, polyester yarn was prepared in the same manner as in Example 1.

[0070] Example 8

[0071] Except for the preparation of a polyethylene terephthalate masterbatch containing 25,000 ppm MWNT as an infrared absorber, the concentration of MWNT in the yarn was 1,000 ppm, and polyester yarn was prepared in the same manner as in Example 1.

[0072] Example 9

[0073] Except for the preparation of a polyethylene terephthalate masterbatch containing 750 ppm graphite as an infrared absorber, the concentration of graphite in the yarn was 30 ppm, and the preparation of polyester yarn was carried out in the same manner as in Example 1.

[0074] Example 10

[0075] Polyester yarn was prepared in the same manner as in Example 1, except that the concentration of graphite in the yarn was 500 ppm after preparing a polyethylene terephthalate masterbatch containing 12,500 ppm of graphite as an infrared absorber.

[0076] Example 11

[0077] Polyester yarn was prepared in the same manner as in Example 1, except that the concentration of graphite in the yarn was 1000 ppm after preparing a polyethylene terephthalate masterbatch containing 25000 ppm graphite as an infrared absorber.

[0078] Experimental Example

[0079] The intrinsic viscosity (IV), yarn strength, infrared absorption properties, etc. of the infrared absorbing masterbatch and polyethylene terephthalate chips prepared in the Examples and Comparative Examples were evaluated and are shown in Tables 1 and 2 below.

[0080] 1) Intrinsic viscosity (IV)

[0081] 0.1 g of the sample was added to a reagent containing a 6:4 (weight ratio) mixture of phenol and 1,1,2,2-tetrachloroethanol. After dissolving for 90 minutes, the solution was transferred to an Ubbelohde intrinsic viscometer (IV) and kept in a constant temperature bath at 30°C for 10 minutes. The fall time of the solution was determined using the intrinsic viscometer (IV) and an aspirator. After determining the fall time of the solvent using the same method, the RV value and IV value were calculated using the following mathematical formula.

[0082] RV = Number of seconds the sample falls / Number of seconds the solvent falls

[0083] IV = 1 / 4(RV-1) / C + 3 / 4(In RV / C)

[0084] In the formula, C represents the concentration of the sample in the solution (g / 100ml).

[0085] 2) Tensile strength of yarn

[0086] After the yarn was placed under standard conditions, i.e. constant temperature and humidity conditions of 25°C and 65%RH, the specimens were measured by tensile testing machine according to ASTM D2256 method.

[0087] 3) Yarn appearance

[0088] During the yarn winding process, use a Strobo scope device to check for 5 minutes. If there is no lint, it is judged as good; if lint is found, it is judged as bad.

[0089] 4) Lightfastness test of yarn

[0090] After the produced yarn was tightly wound into four layers on a plastic plate using a yarn winding machine, a light-resistance test was conducted continuously for 200 hours using a Weather-o-meter device under the conditions of xenon lamp, light intensity of 1.2W / m2 (wavelength 420nm), distance between sample and light source of 350mm, black plate temperature of 63℃, and relative humidity of 30%.

[0091] 5) Yarn reflectivity (infrared absorption)

[0092] The reflectance of the yarn in the 300~3000nm range was measured using a UV-VIS-NIR spectrophotometer (SHIMADZU, UV-3600 model). The lower the reflectance in 950nm, the better the infrared absorption performance.

[0093] 6) Infrared camera image measurement

[0094] In a darkroom, the yarn was tilted backward at a 30° angle, and an infrared camera (IRON VTR8) was used to capture images at a distance of 1m. The results are shown in Figure 1. The darker the image appears in the infrared camera image, the better the infrared absorption performance.

[0095] Table 1 distinguish Example 1 2 3 4 5 6 7 8 9 10 11 Infrared absorbing pigments carbon black SWNT MWNT graphite Infrared absorber concentration in yarn (ppm) 30 5000 10000 30 1000 30 400 1000 30 500 1000 yarn strength (g / d) 9.32 8.51 8.07 9.14 8.76 9.05 8.79 8.38 9.09 8.82 8.61 Yarn appearance good good good good good good good good good good good Yarn reflectivity (950nm,%) 68.8 20.0 8.6 69.1 29.9 69.3 48.6 26.5 69.7 41.5 26.8 Reflectance after lightfastness test (200h) (950nm,%) 68.9 21.1 10.3 69.1 30.3 69.3 48.9 27.3 69.8 42.2 29.0

[0096] Comparative Example 1

[0097] Polyester yarn was prepared in the same manner as in Example 1, except that polyethylene terephthalate masterbatch containing infrared absorbers was not included, and only polyethylene terephthalate chips with an intrinsic viscosity (IV) of 1.05 dl / g were used.

[0098] Comparative Example 2

[0099] Except for the preparation of a polyethylene terephthalate masterbatch containing 500 ppm carbon black as an infrared absorber, the concentration of carbon black in the yarn was 20 ppm. Polyester yarn was prepared in the same manner as in Example 1.

[0100] Comparative Example 3

[0101] Except that the concentration of carbon black in the yarn was 11,000 ppm after preparing a polyethylene terephthalate masterbatch containing 275,000 ppm carbon black as an infrared absorber, polyester yarn was prepared in the same manner as in Example 1.

[0102] Comparative Example 4

[0103] Except that the polyester yarn was prepared in the same manner as in Example 1, after preparing a polyethylene terephthalate masterbatch containing 625 ppm of SWNT as an infrared absorber, the concentration of SWNT in the yarn was 25 ppm.

[0104] Comparative Example 5

[0105] Except that the concentration of MWNT in the yarn was 20 ppm after preparing a polyethylene terephthalate masterbatch containing 500 ppm of MWNT as an infrared absorber, the polyester yarn was prepared in the same manner as in Example 1.

[0106] Comparative Example 6

[0107] Polyester yarn was prepared in the same manner as in Example 1, except that a polyethylene terephthalate masterbatch containing 625 ppm graphite as an infrared absorber was prepared and then subjected to solid-state polymerization, resulting in a graphite concentration of 25 ppm in the yarn.

[0108] Comparative Example 7

[0109] Except for the preparation of a polyethylene terephthalate masterbatch containing 2500 ppm of metal phthalocyanine as an infrared absorber, the concentration of metal phthalocyanine in the yarn was 100 ppm, and the preparation was carried out in the same manner as in Example 1.

[0110] Comparative Example 8

[0111] Except for preparing a polyethylene terephthalate masterbatch containing 2000 ppm tungsten oxide as an infrared absorber, the concentration of tungsten oxide in the yarn was 80 ppm, and the polyester yarn was prepared in the same manner as in Example 1.

[0112] Comparative Example 9

[0113] Except that the concentration of copper pyrophosphate in the yarn was 80 ppm after preparing a polyethylene terephthalate masterbatch containing 2000 ppm copper pyrophosphate as an infrared absorber, polyester yarn was prepared in the same manner as in Example 1.

[0114] Table 2 distinguish Comparative example 1 2 3 4 5 6 7 8 9 Infrared absorbing pigments Not placed carbon black SWNT MWNT graphite Metal Phthalocyanine Tungsten oxide Copper pyrophosphate Concentration of infrared absorber in yarn (ppm) - 20 11000 25 20 25 100 80 80 yarn strength (g / d) 9.35 9.12 7.92 9.19 9.21 9.18 8.67 8.65 8.75 Yarn appearance good good bad good good good bad bad bad Yarn reflectivity (950nm,%) 76.7 71.2 7.3 70.2 72.5 74.0 62.8 63.5 63.7 Reflectance after lightfastness test (200h) (980nm,%) 76.7 71.2 9.2 70.2 72.5 71.1 69.3 70.3 72.2

[0115] Referring to Tables 1 and 2, it can be confirmed that the yarns prepared by the methods of Examples 1 to 11 of the present invention have a strength of 8.0 g / d or higher, good appearance quality, and a reflectance as low as 70% or less, exhibiting the characteristic of further absorbing light in the infrared region. In contrast, the yarn of Comparative Example 1, as a common polyester yarn without infrared absorption properties, has a reflectance as high as 76.6%. The yarns of Comparative Examples 2, 4, 5, and 6 show a trend towards reflectances as high as 70% or more. The yarns of Comparative Examples 3, 7, 8, and 9 suffer from poor appearance quality due to the presence of fuzz.

[0116] Industrial availability

[0117] The infrared-absorbing high-strength polyester yarn of this invention can be used in vehicle seat belts. Recently developed vehicles are equipped with occupant protection devices that provide optimal protection by detecting the seat belt usage status or posture of passengers. When the infrared-absorbing polyester yarn of this invention is applied to vehicle seat belts, accurate information about the seat belt's usage status can be obtained, thereby improving performance and more effectively utilizing the seat belt's protective function.

[0118] The present invention has been described above with reference to preferred embodiments. Those skilled in the art should understand that the present invention can be modified and altered in various ways without departing from the spirit and technical scope of the invention as described in the following claims. Therefore, the technical scope of the present invention should not be limited to the details described in the specification, but should be determined by the claims.

Claims

1. A high-strength infrared-absorbing polyester yarn comprising a carbon-based infrared absorber that absorbs light in the near-infrared region with wavelengths from 750 nm to 3000 nm, composed of polyethylene terephthalate with an intrinsic viscosity (IV) of 0.7 dl / g to 1.0 dl / g and a strength of 8.0 g / d or higher.

2. The high-strength infrared-absorbing polyester yarn as requested in item 1, wherein, The carbon-based infrared absorber is carbon black, graphite, carbon nanotubes, or carbon nanofibers.

3. The high-strength infrared-absorbing polyester yarn as described in claim 2, wherein, The carbon black has a particle size of 10 nm to 50 nm and a specific surface area of ​​90 m² / g to 110 m² / g.

4. The high-strength infrared-absorbing polyester yarn as described in claim 2, wherein, The carbon nanotubes are single-walled carbon nanotubes (SWNTs), multi-walled carbon nanotubes (MWNTs), or composites thereof, and the diameter of the carbon nanotubes is from 1 nm to 50 nm.

5. The high-strength infrared-absorbing polyester yarn as requested in item 1, wherein, The content of the carbon-based infrared absorber is from 30 ppm to 10,000 ppm based on the total weight of the high-strength infrared-absorbing polyester yarn.

6. The high-strength infrared-absorbing polyester yarn as requested in item 1, wherein, The yarn has a reflectivity of less than 70% at a wavelength of 950 nm.

7. A method for preparing high-strength infrared-absorbing polyester yarn, wherein, include: The steps are as follows: preparing a polymer by mixing and melting a carbon-based infrared absorber containing light in the near-infrared region with an intrinsic viscosity (IV) of 0.7 dl / g to 1.0 dl / g with polyethylene terephthalate masterbatch containing light in the near-infrared region with an absorption wavelength of 750 nm to 3000 nm with polyethylene terephthalate chips with an intrinsic viscosity (IV) of 1.0 dl / g to 1.2 dl / g; and obtaining polyester yarn by spinning the polymer.

8. The method for preparing high-strength infrared-absorbing polyester yarn as claimed in claim 7, wherein, The carbon-based infrared absorber is carbon black, graphite, carbon nanotubes, or carbon nanofibers.

9. A method for preparing high-strength infrared-absorbing polyester yarn as claimed in claim 8, wherein, The carbon nanotubes are single-walled carbon nanotubes, multi-walled carbon nanotubes, or composites thereof, and the diameter of the carbon nanotubes is from 1 nm to 50 nm.

10. A method for preparing high-strength infrared-absorbing polyester yarn as claimed in claim 7, wherein, The content of the carbon-based infrared absorber is from 30 ppm to 10,000 ppm based on the total weight of the high-strength infrared-absorbing polyester yarn.

11. A seat belt, wherein, It is made from any of the high-intensity infrared-absorbing polyester yarns in claims 1 to 6.

Images