Lightfast aromatic or heteroaromatic ring yarns and fabrics thereof

Abstract

The application provides a light-aging-resistant aromatic ring or aromatic heterocycle yarn and fabric thereof, the yarn comprising a core yarn and a coating yarn, the core yarn being a filament of aromatic ring or aromatic heterocycle fiber, and the coating yarn containing inorganic particles, the average particle size of the inorganic particles being in the range of 100nm-1100nm, and the content of the inorganic particles being 1-20%. The yarn is woven into a fabric, and the fabric is further subjected to an anti-ultraviolet finishing to further improve the light-aging-resistant effect. The application has the following advantages: mainly using the scattering of inorganic particles to light to protect the aromatic ring or aromatic heterocycle fiber, using the inorganic particles with a reasonable distribution of particle size to achieve the blocking of full spectrum, especially the blue-violet light and near-infrared spectrum. Secondly, the application uses a higher particle concentration to achieve higher protection. Finally, the aromatic ring or aromatic heterocycle fiber is mostly yellow and cannot be dyed, and through this way, the aromatic ring or aromatic heterocycle fiber can be endowed with rich colors.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of high performance fibers, and particularly relates to a light-aging-resistant aromatic ring or aromatic heterocyclic ring yarn and a fabric thereof. BACKGROUND

[0002] High performance fibers are a kind of fibers with special physical and chemical structures and one or more performance indexes significantly higher than ordinary fibers in the field of polymer fiber materials in recent years. These performances include high strength and high modulus, high temperature resistance, flame resistance, corrosion resistance, etc. There are many varieties of high performance fibers, such as carbon fibers, aromatic polyamide fibers, aromatic polyester fibers, aromatic heterocyclic polymer fibers, high-strength and high-modulus polyolefin fibers, and ceramic fibers, which all belong to the category of high performance fibers.

[0003] Among the above-mentioned fibers, aromatic polyamide fibers, aromatic polyester fibers and aromatic heterocyclic polymer fibers have common structural characteristics, i.e. containing aromatic rings or aromatic heterocyclic rings in the main chain. Similar structures endow them with similar characteristics, such as high strength, high modulus, wear resistance, cut resistance, creep resistance, high temperature resistance, etc. They can be widely used as bulletproof vests, protective clothing, composite materials and aerospace materials. Among them, aromatic polyamide fibers are called aramid fibers, aromatic polyester fibers are called polyarylate fibers, and aromatic heterocyclic polymer fibers include polybenzimidazole fibers (PBI fibers), poly-p-phenylene benzobisoxazole (PBO fibers), poly(2,5-dihydroxy-1,4-phenylene pyridine bisimidazole) fibers (PIPD fibers, also known as M5 fibers), polyimide (PI fibers), etc.

[0004] Taking aramid and polyarylate as examples, the special safety airbag of the Mars Explorer landing vehicle uses polyarylate fibers, and the parachute of the Spirit Mars vehicle uses aramid fibers. The large-sized Chinese flag used in the National Day 70th anniversary parade also uses aramid materials.

[0005] The above-mentioned characteristics make aromatic ring and aromatic heterocyclic ring fibers particularly suitable for use in upper fabrics. High performance uppers require lighter weight, higher strength, higher air permeability, better toughness and bending resistance. Compared with other materials such as ultrahigh molecular weight polyethylene fibers, aromatic ring and aromatic heterocyclic ring fibers are more resistant to high temperature and can undergo heat setting and heat bonding processes.

[0006] However, aromatic and heterocyclic aromatic fibers also have their own drawbacks. Their molecular backbone contains numerous aromatic and heterocyclic aromatic rings, forming a conjugated structure of large π bonds. This conjugated structure lowers the energy levels between molecular orbitals, allowing them to absorb wavelengths of 290-420 nm, thus being excited to unstable electronically excited states. These excited states require energy dissipation through various photophysical or photochemical processes to return to their ground state. Photophysical processes generally include: emitting fluorescence or phosphorescence, internal heat conversion, and energy transfer to other molecules. If excited-state molecules fail to dissipate energy through these photophysical processes in a timely manner, the material will undergo photochemical changes, i.e., the breaking of chemical bonds, leading to reduced fiber strength, decreased toughness, and fading.

[0007] For shoe upper fabrics, resistance to light aging is a basic requirement.

[0008] Patent CN101851856A discloses a method for preparing TiO2 hydrosol via a sol-gel method, and then impregnating a mixed coating containing hydrosol and UV absorber onto the fiber surface using ultrasonic treatment. After drying, a UV-resistant polyaryl fiber is obtained. However, this coating exhibits poor adhesion and water washability.

[0009] Patent CN114606761A discloses a method to improve the durability and long-term aging resistance of aramid fibers by coating the surface of the fibers with two layers of anti-transmission coating. However, this method requires fiber activation and is complex, making it unsuitable for the textile industry.

[0010] Patent CN105332275B discloses a method that improves the aging resistance of aramid fibers by adding ultraviolet absorbers and fluorescent whitening agents to the spinning solution. However, this method is only suitable for customized production by fiber manufacturers and is not suitable for the textile industry. Summary of the Invention

[0011] In view of the problems of poor light aging resistance, poor coating process adhesion or complex process of existing aromatic ring and heterocyclic fibers, the present invention provides an aromatic ring or heterocyclic yarn and its fabric that is resistant to light aging.

[0012] The technical solution of the present invention is as follows: A light-resistant aromatic or heterocyclic yarn, comprising a core yarn and a covering yarn, wherein the core yarn is a filament of aromatic or heterocyclic fiber, and the covering yarn contains inorganic particles, wherein the average particle size of the inorganic particles ranges from 100nm to 1100nm; and the content of inorganic particles is 1-20%.

[0013] Furthermore, the core yarn includes one or more of aromatic polyamide fibers, aromatic polyester fibers, and aromatic heterocyclic polymer fibers.

[0014] Further, the covering yarns include one or more of polyamide, polyester, spandex, cupro, acrylic, modacrylic, polyvinyl chloride, polyvinyl alcohol, polytetrafluoroethylene, polyethylene terephthalate, polypropylene, viscose, nitrate, and renewable cellulose.

[0015] Further, the covering yarns are filaments and / or staple fibers.

[0016] Further, the core yarn and the covering yarn have a fineness ranging from 10D to 1600D.

[0017] Further, the inorganic particles include one or more of titanium dioxide, silicon dioxide, barium sulfate, zinc oxide, antimony oxide, magnesium oxide, zinc white, zinc sulfide, calcium silicate, aluminum silicate, silicon carbide, calcium carbonate, silicon nitride, aluminum oxide, iron oxide, zirconium oxide, and jade powder.

[0018] Further, the inorganic particles are preferably silicon-aluminum coated inorganic particles.

[0019] Further, the average particle size of the inorganic particles preferably uses a mixture of inorganic particles of 380nm, 600nm, and 1000nm.

[0020] The present application also provides a light-aging-resistant aromatic or heteroaromatic fabric directly knitted or blended knitted from the light-aging-resistant aromatic or heteroaromatic yarn described above.

[0021] Further, the light-aging-resistant aromatic or heteroaromatic fabric described above is subjected to anti-ultraviolet finishing.

[0022] The advantages of the present application are that the covering yarns containing inorganic particles are used to protect the aromatic or heteroaromatic fibers that are prone to photodegradation. The present application mainly utilizes the scattering of light by inorganic particles to achieve protection of the aromatic or heteroaromatic fibers. The particle size of the inorganic particles used has a reasonable distribution to achieve blocking of the full spectrum of light. In particular, the blue-violet light and near-infrared spectrum are also well blocked. Secondly, the present application uses a higher particle concentration to achieve higher protection. Finally, when the yarn is knitted into fabric, it can be conveniently finished with anti-ultraviolet to further improve the light resistance of the fabric. The above three mechanisms work together to achieve the maximum protection of the aromatic or heteroaromatic fibers.

[0023] In addition, due to the high glass transition temperature of the aromatic or heteroaromatic fibers, the surface is smooth and it is difficult to absorb or adsorb anti-ultraviolet additives, so compared to the method of finishing the fabric with anti-ultraviolet after the fibers are not covered, the covering method is equivalent to permanently "absorbing" a large amount of anti-ultraviolet additives in the aromatic or heteroaromatic fibers, and the effect is better and more durable.

[0024] Finally, the aromatic or heteroaromatic ring fiber is mostly yellow and cannot be dyed, and in this way, the aromatic or heteroaromatic ring fiber fabric can be given rich colors. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0026] The light-aging-resistant aromatic or heteroaromatic ring yarn provided by the present application comprises a core yarn and a coating yarn. The core yarn is a filament of the aromatic or heteroaromatic ring fiber, and comprises one or more of aromatic polyamide fiber, aromatic polyester fiber, and heteroaromatic polymer fiber. The coating yarn can be one or more of nylon, polyester fiber, spandex, cupro fiber, acrylic fiber, modacrylic fiber, polyvinyl chloride fiber, polyvinyl alcohol fiber, polytetrafluoroethylene fiber, ethylene fiber, polypropylene fiber, viscose fiber, nitrate fiber, and renewable cellulose fiber.

[0027] The inorganic particles in the coating yarn have an average particle size range covering the wavelength range (250-3000 nm) of the sunlight spectrum, so as to achieve all-around protection of the fiber, including covering ultraviolet light (<400 nm), visible light (400-760 nm), and near-infrared light (760-3000 nm). The particle size range is 100 nm-1100 nm.

[0028] The obtained coating yarn can also be subjected to ultraviolet-resistant finishing, which aims to provide additional protection for the upper fabric and reduce the aging degradation caused by the exposure of the core yarn due to the loose coating. The ultraviolet-resistant finishing can be performed on the coating yarn or the fabric knitted from the coating yarn.

[0029] The coating yarn can be a filament and / or a staple fiber.

[0030] The fineness of the core yarn and the coating yarn ranges from 10D to 1600D; preferably, the fineness of the core yarn and the coating yarn ranges from 50D to 1000D; more preferably, the fineness of the core yarn and the coating yarn ranges from 50D to 200D.

[0031] The inorganic particles include one or more of titanium dioxide, silicon dioxide, barium sulfate, zinc oxide, antimony oxide, magnesium oxide, lithopone, zinc sulfide, calcium silicate, aluminum silicate, silicon carbide, calcium carbonate, silicon nitride, aluminum oxide, iron oxide, zirconium oxide, jade powder, etc. Preferably, the inorganic particles include one or more of titanium dioxide, silicon dioxide, barium sulfate, zinc oxide, aluminum oxide, zirconium oxide, lithopone, calcium silicate. More preferably, the inorganic particles include one or more of titanium dioxide, barium sulfate, zinc oxide, calcium silicate. Even more preferably, the inorganic particles are titanium dioxide. Most preferably, the inorganic particles are rutile titanium dioxide.

[0032] Compared with the inorganic particles alone, the selection of the silicon-aluminum coated inorganic particles can further reduce the photocatalytic activity of the inorganic particles, and achieve the strengthening of the inorganic particles on the ultraviolet resistance of the coated yarn.

[0033] The average particle size of the inorganic particles is preferably a mixture of inorganic particles with an average particle size of 380 nm, 600 nm and 1000 nm. More preferably, the mass ratio of the mixture of inorganic particles with an average particle size of 380 nm, 600 nm and 1000 nm is 5:2:0.5.

[0034] The content of the inorganic particles is 1-20%; preferably, the content of the inorganic particles is 2-10%; more preferably, the content of the inorganic particles is 3-6%.

[0035] Preferably, the coated yarn is woven into a fabric and then subjected to ultraviolet resistance finishing.

[0036] The present application controls the content and particle size of the inorganic particles in the coated yarn to achieve light aging protection of the aromatic ring and heterocyclic aromatic fiber. The light sensitive band of the aromatic ring and heterocyclic aromatic fiber generally covers the band of 350-420 nm. The inorganic particles have weak absorption of light in the band of 370-420 nm, and this band is mainly blocked by scattering. The blue-violet light (400-420 nm) band of visible light can also excite the fiber and cause the breakage of chemical bonds. In addition, the visible light in the solar spectrum, especially the near-infrared part (760-2500 nm), can produce a thermal effect, and when irradiated onto the fiber, it can heat the fiber. According to the Arrhenius equation, an increase in temperature can significantly accelerate the rate of degradation, so near-infrared also has an accelerating effect on degradation.

[0037] According to the Mie scattering principle, when the wavelength of light is comparable to the size of the particles in the medium, the particles have the maximum scattering efficiency of light. Therefore, in order to achieve the most effective scattering of the ultraviolet-visible-near-infrared band in the solar spectrum, the particle size range of the inorganic particles should cover the wavelength range of the solar spectrum (250-3000 nm) to achieve all-round protection of the fiber.

[0038] Meanwhile, in the process of fiber production, the difference between the refractive index of inorganic particles and polymer matrix is large, which can scatter the sunlight spectrum more. Some inorganic particles not only can reflect, scatter and refract visible light-near infrared, but also can strongly absorb ultraviolet light in the wavelength range of 280-370 nm, such as titanium dioxide, zinc oxide, etc. According to the Mie scattering law, the refractive index has a great influence on the distribution of scattered light field. The refractive index can be written as:

[0039] N = n r + in i

[0040] Wherein, the real part n r determines the propagation speed of light in the medium (v = c / n r ), and the imaginary part n i represents the attenuation of light in the medium, and the relationship between it and the absorption coefficient a of the medium is a = 4πn i / λ, λ is the wavelength of light. Therefore, the scattering light intensity of the absorbing substance is much weaker than that of the non-absorbing substance.

[0041] According to Lambert-Bill law, the absorption of light by inorganic particles in the wrapping yarn is proportional to the concentration and light absorption coefficient of the particles. The higher the concentration and light absorption coefficient, the lower the light intensity transmitted (i.e. into the core yarn).

[0042] These particles often have photocatalytic activity, and after absorbing ultraviolet light, they will produce holes h + and e - , in which the hole has strong oxidizing property and also causes the degradation of the polymer. However, if silicon-aluminum coated particles are used, the absorption of ultraviolet light by inorganic particles can be reduced, for example: using silicon-aluminum coated titanium dioxide particles, the photocatalytic activity of titanium dioxide is reduced, which is beneficial to improve the ultraviolet resistance of the wrapping yarn itself, and the outer wrapping yarn can provide more durable protection for the core yarn of aromatic or heterocyclic fiber.

[0043] The following takes titanium dioxide and silicon oxide as inorganic particles and polyester yarn as wrapping yarn to further illustrate the technical effect of the present application.

[0044] Example 1

[0045] The core yarn is 200D polyarylate yarn, and the wrapping yarn uses two 150D polyester yarns. The polyester yarn contains 1% of rutile type titanium dioxide, and the average particle size of the titanium dioxide is 380 nm. The strength of the wrapped yarn is 45.2N. The single wrapped yarn is put into a xenon lamp aging box, and after 24h of xenon lamp irradiation, the strength is 32.5N, and the retention rate is 72%.

[0046] Example 2

[0047] The core yarn is 200D polyarylate yarn and the cover yarn is two 150D polyester yarns. The polyester yarns contain 4% of rutile titanium dioxide. The average particle size of the titanium dioxide is 380 nm. The strength of the covered yarn is 44.8 N. The single covered yarn is put into a xenon lamp aging oven and after 24 h of xenon lamp irradiation, the strength is 37.4 N and the strength retention rate is 84%.

[0048] Example 3

[0049] The core yarn is 200D polyarylate yarn and the cover yarn is two 150D polyester yarns. The polyester yarns contain 4% of rutile titanium dioxide. Three different particle size mixtures of titanium dioxide are used, with average particle sizes of 380 nm, 600 nm and 1000 nm. The weight ratio of the three titanium dioxides is 5:2:0.5. The strength of the covered yarn is 44.2 N. The single covered yarn is put into a xenon lamp aging oven and after 24 h of xenon lamp irradiation, the strength is 38.0 N and the strength retention rate is 86%.

[0050] Example 4

[0051] The core yarn is 200D polyarylate yarn and the cover yarn is two 150D polyester yarns. The polyester yarns contain 4% of rutile titanium dioxide coated with silicon and aluminum. Three different particle size mixtures of rutile titanium dioxide coated with silicon and aluminum are used, with average particle sizes of 400 nm, 620 nm and 1000 nm. Unlike Example 3, the three titanium dioxides are all rutile titanium dioxide coated with silicon and aluminum. The weight ratio of the three titanium dioxides is 5:2:0.5. The strength of the covered yarn is 44.0 N. The single covered yarn is put into a xenon lamp aging oven and after 24 h of xenon lamp irradiation, the strength is 38.2 N and the strength retention rate is 87%.

[0052] Example 5

[0053] The core yarn is 200D polyarylate yarn and the cover yarn is two 150D polyester yarns. The polyester yarns contain 4% of zinc oxide. The particle size distribution range is 100 nm-1100 nm, with an average particle size of 580 nm. The strength of the covered yarn is 43.9 N. The single covered yarn is put into a xenon lamp aging oven and after 24 h of xenon lamp irradiation, the strength is 38.3 N and the strength retention rate is 87%.

[0054] Example 6

[0055] The core yarn is 200D polyarylate yarn, and the covering yarn is two strands of 150D polyester yarn. The polyester yarn contains 10% titanium dioxide and 10% zinc oxide. The average particle size of the titanium dioxide is 380 nm, and the average particle size of the zinc oxide is 580 nm. The strength of the covered yarn is 41.4N. The single covered yarn is placed in a xenon lamp aging box, and after 24h of xenon lamp irradiation, the strength is 36.4N, and the strength retention rate is 88%. However, due to the high content of inorganic particles, the polyester yarn is difficult to spin, and the dispersion of inorganic particles is poor, and the overall yarn strength is low.

[0056] Example 7

[0057] The covered polyarylate yarn in Example 4 is woven into a plain fabric, where the weft direction is the covered polyarylate yarn, and the warp direction is polyester low-elasticity filament. The fabric is subjected to anti-ultraviolet finishing, and the weft direction strength after finishing is 1000N. The finished fabric is placed in a xenon lamp aging box, and after 24h of xenon lamp irradiation, the weft direction strength is 910N, and the strength retention rate is 91%.

[0058] Example 8

[0059] The core yarn is 100D para-aramid yarn, and the covering yarn is two strands of 75D nylon 6. The nylon 6 contains 4% rutile-type titanium dioxide. The average particle size of the titanium dioxide is 380 nm. The strength of the covered yarn is 19.0N. The single covered yarn is placed in a xenon lamp aging box, and after 24h of xenon lamp irradiation, the strength is 16.3N, and the strength retention rate is 86%.

[0060] Comparative Example 1

[0061] The core yarn is 200D polyarylate yarn, and the covering yarn is two strands of ordinary 150D polyester yarn. The strength of the covered yarn is 45.6N. The single covered yarn is placed in a xenon lamp aging box. After 24h of xenon lamp irradiation, the yarn strength is 29.6N, and the strength retention rate is 65%.

[0062] Comparative Example 2

[0063] The core yarn is 100D para-aramid yarn, and the covering yarn is two strands of ordinary 75D nylon 6. The strength of the covered yarn is 19.7N. The single covered yarn is placed in a xenon lamp aging box. After 24h of xenon lamp irradiation, the yarn strength is 13.6N, and the strength retention rate is 69%.

[0064] Comparative Example 3

[0065] The 200D polyarylate yarn is not covered. The yarn strength is 37.2N. The single yarn is placed in a xenon lamp aging box. After 24h of xenon lamp irradiation, the strength is 18.9N. The strength retention rate is 51%.

[0066] Comparative Example 4

[0067] 100D para-aramid yarn, uncoated. The yarn strength is 17.3N. A single yarn is put into the xenon lamp aging box. After 24h of xenon lamp irradiation, the strength is 9.7N. The strength retention rate is 56%.

[0068] Comparative Example 5

[0069] 50D polyarylate yarn, 1% rutile titanium dioxide with an average particle size of 50nm is added during the spinning process. It should be noted that the larger the average particle size of titanium dioxide, the greater the impact on the strength of the polyarylate yarn, so in order to maximize the strength of the polyarylate and have anti-photobleaching effect, titanium dioxide with an average particle size of 50nm is selected; the strength of the polyarylate yarn is 8.6N. A single yarn is put into the xenon lamp aging box, and after 24h of xenon lamp irradiation, the strength is 5.4N, and the strength retention rate is 60%. It can be seen that adding titanium dioxide with a smaller average particle size to the polyarylate spinning solution can absorb ultraviolet light, but due to the low scattering efficiency of ultraviolet light, it is transparent to visible light, and cannot effectively improve the light aging resistance of polyarylate.

[0070] Comparative Example 6

[0071] A 200D polyarylate yarn is woven into a plain fabric, with polyarylate yarn in the weft direction and polyester low-elasticity filament in the warp direction. The fabric is subjected to anti-ultraviolet finishing. The weft direction strength after finishing is 920N. The finished fabric is put into the xenon lamp aging box, and after 24h of xenon lamp irradiation, the weft direction strength is 450N, and the strength retention rate is 49%.

[0072] Comparative Example 7

[0073] The coated polyarylate in Comparative Example 1 is woven into a plain fabric, with coated polyarylate yarn in the weft direction and polyester low-elasticity filament in the warp direction. The fabric is subjected to anti-ultraviolet finishing. The weft direction strength after finishing is 1020N. The finished fabric is put into the xenon lamp aging box, and after 24h of xenon lamp irradiation, the weft direction strength is 820N, and the strength retention rate is 80%.

[0074] From the above examples, it can be seen that the form of adding inorganic particles to the coated yarn is better than the form of directly adding inorganic particles to the aromatic ring or heteroaromatic ring fiber in terms of light aging resistance protection of the aromatic ring or heteroaromatic ring fiber; it can better maintain the strength of the aromatic ring or heteroaromatic ring yarn fabric, and the anti-ultraviolet finishing of the fabric is better. The light aging resistance effect is better. The dilemma of light aging of aromatic ring and heteroaromatic ring fiber used on the vamp is solved.

[0075] The above merely describes the preferred embodiments of the present application, and is not intended to limit the present application in any form. Although the present application has been disclosed with the preferred embodiments as above, it is not intended to limit the present application, and any person skilled in the art can make some changes or modifications to the above-mentioned technical content with the prompt as equivalent embodiments of equivalent changes without departing from the technical solution of the present application. Any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application, which does not depart from the technical solution of the present application, still belongs to the scope of the present application.

Claims

1. A lightfast, aromatic ring yarn, characterized in that, The core yarn is 200D polyarylate yarn, and the covering yarn is two 150D polyester yarns; the polyester yarns contain 4% silicon-aluminum coated rutile titanium dioxide, and a mixture of three different particle sizes of silicon-aluminum coated rutile titanium dioxide is used, the average particle sizes of which are 400 nm, 620 nm and 1000 nm respectively; the weight ratio of the three kinds of titanium dioxide is 5:2:0.5; the strength of the coated yarn is 44.0 N; after a single yarn is put into a xenon lamp aging oven and irradiated by a xenon lamp for 24 h, the strength is 38.2 N, and the strength retention rate is 87%.

2. A lightfast aromatic ring fabric, characterized by, The light-aging-resistant aromatic ring yarn as claimed in claim 1 is directly knitted or blended and knitted.

3. The lightfast aromatic ring fabric of claim 2, wherein, The light-aging-resistant aromatic ring fabric is subjected to anti-ultraviolet finishing.