WO2022033412A1 - Multi-layer section composite fiber and fabric thereof - Google Patents

Abstract

A multi-layer section composite fiber. A cross section of the fiber has a multi-layer section structure of 3-15 layers formed by alternately arranging at least two components; the outermost layer of the multi-layer section structure is formed of polymer B having an inorganic particle content of 5.0 wt% or less; at least one layer in the composite fiber is formed of polymer A having an inorganic particle content of 10.0-70.0 wt%, and polymer A accounts for 10-70 wt% of the composite fiber. The obtained fiber and fabric have good spinning and weaving processing performance, and have excellent anti-permeability, anti-ultraviolet, heat shielding performance and excellent resistance to water immersion and discoloration.

Description

Multilayer section composite fiber and its fabric technical field

The present invention relates to a multi-layer cross-section composite fiber, in particular to a multi-layer cross-section composite fiber formed by alternately arranging at least two polymers with different inorganic particle contents, and a fabric obtained from the fiber.

Background technique

In the field of wear, visual occlusion is an important performance of textiles, which is related to the most basic function of shading; in the field of decoration and military, it involves special visual requirements such as one-way perspective and camouflage. In addition, with the extensive use of Freon worldwide and the increasingly serious environmental pollution, the ozone layer in the atmosphere has been severely damaged. Long-term exposure to ultraviolet rays will reduce the lifespan of organic molecules and reduce the immune function of the human body, which not only damages the skin and causes dermatitis, erythema, freckles and skin cancer, but also promotes eye diseases and causes cataract disease. In addition, especially in hot summer, clothing with certain heat shielding properties has become the pursuit of consumers.

In addition, in the field of wearing, the discoloration of clothing is also an important property of textiles. After the human body sweats a lot or is wet by rain, the clothes will be close to the skin, and the place soaked by sweat or rain will be lighter than the dry place. Darkens, affects aesthetics. Furthermore, in the process of exercising, competitive opponents can often judge the fatigue level of the opponent's players by the amount of sweat of the opponent's players, so as to reasonably use competitive means to win the game. Therefore, when the clothing is soaked, it will not fade and become an emerging pursuit of summer consumers.

Chinese patent CN103628180A discloses a super-extinction memory fiber and a preparation method. The fiber adopts a skin-core composite structure, which cannot overcome the phenomenon of wire breakage in the weaving process of conventional fully matte fibers. A large amount of titanium dioxide particles are added in the core to achieve the anti-penetration effect, and the amount of titanium dioxide in the sheath is lower than that of the core. Improve weaving passability. However, the amount of titanium dioxide added in the composite fiber core is greater than or equal to 3%. If a large amount of titanium dioxide is added, although excellent anti-penetration and anti-ultraviolet effects are obtained, it will lead to a decrease in spinnability, a decrease in the strength of the raw yarn, and the interruption of the yarn during the weaving process. Obviously, adding a large amount of titanium dioxide will also lead to an increase in cost. On the contrary, if the amount of titanium dioxide added is low, although it has the performance of conventional full extinction, it does not have excellent anti-penetration and anti-ultraviolet effects.

Japanese Patent Laid-Open No. 11-269721, No. 2008-223171, and No. 2013-44055 also disclose a skin-core composite fiber, which achieves anti-penetration and anti-ultraviolet effects by adding titanium dioxide particles to the core component. Likewise, titanium dioxide is added in large quantities in the composite fiber core. Although excellent anti-penetration and anti-ultraviolet effects are obtained, it will lead to a decrease in spinnability, a decrease in the strength of the raw yarn, and obvious interruption of the yarn during the weaving process, and a large amount of titanium dioxide will also lead to an increase in cost. On the contrary, if the amount of titanium dioxide added is low, Although it has the performance of conventional full extinction, it does not have excellent anti-penetration and anti-ultraviolet effects.

Japanese Patent Laid-Open No. 11-181627 discloses a multi-layer laminated fiber, a polyester composite staple fiber with excellent spinnability, opacity and heat shielding properties, composed of two types of polyesters with different white pigment contents, wherein the white pigment The content of the white pigment in the polyester with more white pigment is 1.5 wt % to 10.0 wt %, and the content of the white pigment in the polyester with less white pigment is less than 0.5 wt %. In the embodiment disclosed in the patent in which there are multiple layers on the fiber cross section such as core sheath or concentric circles, polyester with more white pigment is used as the innermost layer, and polyester with less white pigment is used as the outer layer, which can avoid spinning Deterioration of silkiness. Compared with the general fully matte polyester, the anti-penetration performance of the fibers obtained in this embodiment is improved, but still cannot achieve a higher anti-penetration effect.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a multi-layer cross-section composite fiber and a fabric formed by the composite fiber with high anti-penetration, anti-ultraviolet, good heat shielding performance, and prevention of discoloration and fading at the same time.

The technical solution of the present invention is:

A multi-layer cross-section composite fiber, which has a multi-layer cross-sectional structure of 3 to 15 layers formed by alternately arranging at least two components in its cross section, and the outermost layer of the multi-layer cross-sectional structure has an inorganic particle content of 5.0 wt% or less. At least one layer of the composite fiber is formed of polymer A with an inorganic particle content of 10.0-70.0 wt %, and the polymer A accounts for 10-70 wt % of the composite fiber.

The content of the inorganic particles derived from the polymer A in the composite fiber is preferably 7.0 to 30.0 wt %, more preferably 8.0 to 20.0 wt %, and most preferably 12.0 to 15.0 wt %.

The content of inorganic particles in the polymer-free A is preferably 15-60 wt%.

The cross-section of the fiber preferably has a cross-sectional structure of 3 to 9 layers formed by alternately arranging polymer A and polymer B, more preferably having 3 to 5 layers formed by alternately arranging polymer A and polymer B sectional structure.

The area of the outermost layer of the multilayer cross-sectional structure preferably accounts for 5 to 30% of the entire cross-sectional area.

The polymer constituting the composite fiber is preferably polyester, nylon, polypropylene or polyurethane.

In the dry and wet state of the composite fiber, the absolute value of the difference in visible light reflectance at a wavelength of 550 nm is preferably less than 5.0%, more preferably less than 3.0%.

The strength-elongation product of the conjugate fiber is preferably 15.0 or more, and more preferably 19.0 or more.

The present invention also discloses a fabric prepared from the above-mentioned multi-layer cross-sectional structural fibers. The absolute value of the difference in the reflectance of visible light with a wavelength of 550 nanometers in the dry and wet state of the fabric is preferably less than 5.0%, more preferably less than 3.0%.

In the present invention, the polymer A with high content of inorganic particles and the polymer B with low content of inorganic particles are alternately arranged in the fiber through the form of multi-layer section, so that the composite fiber has good anti-penetration, anti-ultraviolet and heat-shielding performance effects. At the same time, good strength and elongation properties are maintained, and the composite fibers and the fabrics formed therefrom can effectively prevent discoloration and fading.

Description of drawings

Figure 1 is a cross-sectional view of a 9-layer concentric circular composite cross-section structural fiber.

Figure 2 is a cross-sectional view of a 3-layer concentric circular composite cross-sectional structural fiber.

Figure 3 is a cross-sectional view of a side-by-side multilayer composite cross-sectional structural fiber.

In FIGS. 1 to 3 , the reference numeral 1 represents the polymer A, and the reference numeral 2 represents the polymer B. As shown in FIG.

detailed description

The multi-layer cross-section composite fiber of the present invention has a multi-layer cross-sectional structure of 3 to 15 layers formed by alternately arranging at least two components, and the outermost layer of the multi-layer cross-sectional structure has an inorganic particle content of 5.0 wt % or less of polymer B, and at least one layer of the conjugate fiber is formed of polymer A with an inorganic particle content of 10.0 to 70.0 wt %.

In the present invention, the polymer A with high content of inorganic particles is placed in the inner layer of the multi-layer cross-section composite fiber, so that the fiber can have good passability during processing, and problems such as broken filaments will not occur in the later weaving process.

Although the higher the content of inorganic particles, the better the anti-permeability of the fiber, but adding a large amount of inorganic particles will significantly reduce the strength and elongation of the fiber. In order to maintain the properties of fiber such as strength and elongation, it is necessary to reduce the amount of polymer A with high inorganic particle content. The anti-penetration effect is better than that of the core-sheath fiber with the same content of inorganic particles.

On the other hand, in order to meet some specific strength and elongation, the fiber can be distributed in the fiber by polymer A in the form of multiple layers, although the composition of the polymer A in the fiber cross section close to the outer layer is reduced, resulting in anti-penetration performance There is a slight decrease, but polymer A is more uniformly dispersed in the fiber through the multi-layer structure, which can improve the strength and elongation of the raw fiber and meet the specific application conditions.

When the content of inorganic particles in the polymer A is less than 10.0 wt%, although the spinning performance of the polymer A and the physical properties of the composite fibers are not problematic, a small amount of inorganic particles is not conducive to the reflection and absorption of light, and the anti-aging properties of the composite fibers. The permeability, UV resistance, and heat shielding performance will be greatly reduced and will not reach the required level. The higher the content of inorganic particles A in the polymer A, the better the anti-penetration, UV resistance, heat shielding performance, and discoloration after being wetted by water of the composite fiber. However, when the content of inorganic particles in the polymer A is higher than 70.0 wt%, the spinning performance of the polymer A is affected, and the phenomenon of yarn breakage and yarn floating easily occurs during the spinning process, and the obtained composite fiber has poor strength and elongation. affect its subsequent use. Therefore, considering comprehensively the anti-permeability, UV resistance, heat shielding performance and production feasibility of the composite fiber, the content of inorganic particles in the polymer A is preferably below 15.0-50.0 wt %.

The polymer A accounts for 10 to 70 wt % of the entire composite fiber. If the content of polymer A in the composite fiber is less than 10wt%, the normal composite multi-layer cross-sectional structure cannot be guaranteed, and the content of inorganic particles in the composite fiber is too small, and the fiber's anti-penetration, anti-ultraviolet, heat shielding properties, water infiltration The later discoloration is not ideal. Although the higher the content of polymer A, the better the anti-permeability of the composite fiber, but the price of the polymer component with a large content of inorganic particles is higher, which leads to an increase in the price of the fiber as a whole. The basic physical properties of the fiber will decrease. In the present invention, the content of the polymer A in the conjugated fiber is preferably 15 to 60 wt %.

The present invention does not specifically stipulate the form of the multi-layer cross-sectional structure, which may be arranged in concentric circles, parallel arrangements, or perpendicularly intersecting arrangements between layers. When the multi-layer cross-sectional structure is arranged in concentric circles, the innermost central layer may be a polymer layer or a hollow layer.

As long as the layers formed by polymer A and the layers formed by polymer B are arranged alternately and at intervals, the alternate arrangement can ensure that when the content of polymer A in the fiber is low, no matter what kind of multi-layer cross-sectional structure the cross-section of the composite fiber presents, All of them can make the composite fiber achieve excellent anti-penetration, anti-ultraviolet, heat shielding performance, and discoloration and fading performance after being soaked in water. At the same time, the alternating arrangement can also ensure the thickness of the outermost layer.

The content of inorganic particles derived from polymer A in the multi-layer cross-section composite fiber of the present invention is 7.0-30.0 wt %, and the content of inorganic particles derived from polymer A in the composite fiber is relatively small, and the fiber has anti-penetration, anti-ultraviolet, and heat shielding properties. Performance and discoloration after being soaked in water are not ideal. Although the higher the content of inorganic particles from polymer A in the composite fiber, the better the performance of the composite fiber, but when the content of inorganic particles from polymer A increases to a certain value, the performance of the overall fiber will be less and less, and due to The price of a polymer component with a high content of inorganic particles is higher, which leads to an increase in the price of the entire fiber, and when the content of inorganic particles is high, the basic physical properties of the fiber will decrease. Therefore, the content of the inorganic particles derived from the polymer A in the fibers of the present invention is preferably 8.0 to 20.0%, and most preferably 12.0 to 15.0%.

The composite fiber of the present invention has a cross-sectional structure of 3 to 15 layers. When the number of layers of the multi-layer cross-sectional structure is too many, more than 15 layers, the forming of the cross-sectional structure will be abnormal, and the basic physical properties of the fibers will be poor. In order to take into account the basic physical properties of the fiber, the anti-penetration performance and the heat shielding performance, in the present invention, the number of layers of the multi-layer cross-sectional structure is preferably 3 to 9 layers, most preferably 3 to 5 layers.

When the content of inorganic particles in the polymer contacting the spinning equipment is high, it will cause friction between the inorganic particles and the yarn guide, etc., which will affect the life of the equipment and the spinnability of the polymer. In order to make the spinnability of the polymer better during spinning, and to avoid the influence of inorganic particles on the spinning equipment, it is preferred in the present invention that the surface of the fiber is exposed to the polymer B with less inorganic particles, that is, the multi-layer cross-sectional structure. The outermost layer is formed of the polymer B. Polymer B with less inorganic particle content covers polymer A with more inorganic particle content, avoiding direct contact of a large number of inorganic particles with the oil feeder, each yarn guide of the spinning machine, rollers, etc. during spinning, reducing frictional resistance , to ensure the good engineering passability of the thread, and to avoid the high content of inorganic particles directly contacting the various parts of the spinning machine to cause falling off, contaminating the oil feeder, yarn guide and roller, and reducing the anti-penetration and resistance to multi-layer cross-section composite fibers. The influence of UV and heat shielding properties can also reduce the wire breakage rate in the post-processing process.

Furthermore, the area of the outermost layer formed of the polymer B preferably accounts for 5 to 30% of the entire cross-sectional area in order not to unduly affect the anti-penetration, UV resistance, and heat shielding properties of the conjugate fiber. When the area ratio of the outermost layer formed of the polymer B is too large, the influence on the barrier property of the entire composite fiber is large, and the barrier property of the composite fiber is deteriorated. Although the smaller the area of the outermost layer formed by the polymer B, the better the anti-permeability of the composite fiber, but when the area ratio is small to a certain extent, the increase in the anti-permeability of the composite fiber is relatively small. And the surface abrasion caused by friction will easily occur during the processing and use of the wire. Therefore, in the present invention, it is more preferable that the area of the outermost layer formed by the polymer B accounts for 10 to 20% of the entire area of the cross section.

The inorganic particles of the present invention can be titanium dioxide, calcium carbonate, barium sulfate, zinc oxide, silicon dioxide or boron nitride, etc., among which titanium dioxide, calcium carbonate, barium sulfate or zinc oxide are preferred. The inorganic particles contained in the polymer A and the polymer B may be the same or different. In order to obtain a composite fiber with higher barrier properties and UV resistance, the inorganic particles in the present invention are preferably titanium dioxide.

The refractive index of the inorganic particles is preferably 1.6 to 3.0, and more preferably 2.0 to 3.0.

According to different crystal forms, the titanium dioxide is divided into anatase titanium dioxide and rutile titanium dioxide. The crystal structure of the commonly used anatase titanium dioxide is unstable, and it is easy to generate free radicals. When the free radicals accumulate to a certain amount, the light fastness of the polymer is affected. Therefore, when a large amount of anatase titanium dioxide is contained in the fiber, the light resistance of the fiber will be deteriorated. In order to obtain better light fastness to the fibers, the inorganic particles contained in the polymer A of the present invention are preferably rutile titanium dioxide.

In the present invention, the polymer components constituting the polymer A are not particularly limited, and include various thermoplastic polymers. It may be a polyester-based polymer or a polyamide-based polymer, a polyolefin-based polymer, or a polyurethane. Specifically, the polyester polymer can be a homopolymer such as polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, etc., or a copolymer thereof. The polyamide-based polymer can be polyamide 6, cationic dye-dyeable polyamide 6, polyamide 66, etc.; the polyolefin-based polymer can be polyethylene, polypropylene, polybutadiene, and the like.

The polymer components constituting the polymer B are not particularly limited in the present invention, and include various thermoplastic polymers. Depending on the polymer raw material, it may be a polyester-based polymer or a polyamide-based polymer, a polyolefin-based polymer, or a polyurethane. Specifically, the polyester polymer can be a homopolymer such as polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, etc., or a copolymer thereof. According to different functions, the polyester polymer can be dyeable polyester with disperse dyes, dyeable polyester with cationic dyes, easily dissolved polyester, conductive polyester, antistatic polyester, hygroscopic polyester, low friction polyester Polyester, etc.; the polyamide polymer can be polyamide 6, cationic dyeable polyamide 6, polyamide 66, etc.; the polyolefin polymer can be polyethylene, polypropylene, polybutadiene, etc. . Depending on the content of inorganic particles in the polymer B, the sheath component can be a bright polymer, a semi-dull polymer, a full-dull polymer, such as a bright polyester, a semi-dull polyester, a full-dull polyester, and the like.

As the polymer B in the outermost layer of the fiber, when various functions are imparted to it, the spinnability will be deteriorated, and the lasting stability of the corresponding functions in subsequent use is not good, you can choose to add functionalities in the outermost layer. The polymer component, as a separate layer, is alternately arranged with polymer A and polymer B, and polymer B is selected to contain only 5.0 wt% or less of inorganic particles. The functional polymer may be a hygroscopic polymer that improves the moisture absorption rate of the entire fiber, an antibacterial polymer that improves the antibacterial property of the entire fiber, a flame retardant polymer, and the like.

The form of the fibers is not particularly limited in the present invention, and may be long fibers or short fibers.

When the fibers are wetted with liquid (wet state), due to the presence of the liquid layer, the refraction and reflection effects are changed compared to the fibers in the usual dry state. If the change is too large, the color of the fiber in the wet state and the dry state will be too different, especially when it is used to prepare summer clothes, the color of the place impregnated by sweat is quite different from the color of other places not impregnated by sweat, which affects the beautiful. In the present invention, the degree of change in the refraction and reflection effects of the fiber in the wet state and the dry state is related to the number of layers of the fiber cross section, the content of inorganic particles in the polymer A and the polymer B, and the content of the polymer A and the polymer B in the composite fiber. have a certain relationship. The degree of change is represented by the absolute value of the difference in visible light reflectivity of the composite fiber at a wavelength of 550 nanometers in wet and dry conditions. In the dry and wet state of the composite fiber of the present invention, the absolute value of the difference in visible light reflectance with a wavelength of 550 nm is preferably less than 5.0%.

The strand strength and elongation product of the multi-layer cross-section composite fiber of the present invention is above 15.0. In the process of fiber use, the strength and elongation product of the raw silk needs to meet a certain level, so as to ensure good passability during spinning, weaving, and product use, and can maintain good tear resistance. When the strength and elongation product of the raw yarn is below 15.0, the yarn will be broken during the weaving process, and the passability will be poor, and the finished product will not have good breaking strength, which will affect the service life.

The conjugated fibers of the present invention can be used to prepare fabrics, and the multi-layer cross-section conjugated fibers of the present invention can be partially or completely used in the fabrics. The fabrics include woven fabrics, knitted fabrics, third fabrics, non-woven fabrics, multidirectional fabrics, three-dimensional fabrics, composite fabrics, and the like. When the composite fibers of the present invention are partially used to prepare the fabric, other fibers may be ordinary polyester fibers, polyamide fibers, polyolefin fibers, polyurethane fibers, and the like. On the premise that the difference in visible light reflectivity of 550 nm wavelength in the dry and wet state of the fabric is less than 5.0%, it can be widely used as a summer wear fabric.

The test method of each parameter involved in the present invention is as follows:

(1) Anti-penetration performance

Using D65 light source to illuminate the whiteboard and blackboard of the reference color respectively, the L values were measured as L (white) and L (black). Then take the fabric sample cloth (10 × 10cm), cover it on the whiteboard and blackboard of the reference color, and then irradiate the sample cloth with D65 light source, and measure its L value as L (white + cloth), L (black + cloth) , and then use the following formula to calculate the data of light barrier properties. The larger the data of the obtained light barrier properties, the better the barrier properties of the sample fabric. 10 samples were taken for testing, and the final results were averaged.

Light barrier: (1-(L(white+cloth)-L(black+cloth))/(L(white)-L(black))×100%.

(2) UPF (UV resistance)

The UV resistance parameter UPF is evaluated according to the standard GB/T 6529. 10 samples were taken for testing, and the final results were averaged. A UPF value of 50 or more was judged as 0, a UPF value of 40 or more and less than 50 was judged as Δ, and a UPF value of less than 40 was judged as ×.

(3) The type and content of inorganic particles in the fabric

Take about 4 g of the fiber fabric, melt the sample, and measure the content of metal elements by X-ray fluorescence spectrometer (manufacturer: Rigaku, model: ZSX Primus III+), and then measure the weight of inorganic particles in the fiber by burning ash method. The element content and the weight of inorganic particles were used to calculate the type and content of inorganic particles in the fabric. 10 samples were taken for testing, and the final results were averaged.

(4) The cross-sectional ratio of each component in the fiber and the area ratio of the outermost layer

The cross-section of the composite fiber was photographed by SEM, the cross-sectional photograph was printed on paper, and the cross-sectional area S ₁ of the polymer B component with a small inorganic particle content and the cross-sectional area S ₂ of the polymer A component with a large inorganic particle content were obtained by an area meter. , the component ratio of polymer B=S ₁ /(S ₁ +S ₂ ), the component ratio of polymer A=S ₂ /(S ₁ +S ₂ ).

For the cross-section of the composite fiber photographed by SEM, the area of the outermost layer and the overall area of the cross-section were measured, and the ratio of the cross-sectional area of the outermost layer = the area of the outermost layer/the area of the entire fiber. 10 samples were taken for testing, and the final results were averaged.

(5) Content of inorganic particles in each component

Take a certain weight (N1) of fiber samples, and measure the metal element weight (calculate the inorganic particle weight M1) by X-ray fluorescence spectrometer (manufacturer: Rigaku, model: ZSX Primus III+). The composite ratio of polymer A and polymer B in the fiber and the area ratio of the outermost layer (test method 4) were determined by the cross-sectional photo, and the ratio of the outermost layer to the whole fiber was obtained. The outermost polymer B was removed at the same rate. With respect to the remaining fibers (weight N2) after the dissolution treatment, the weight of the metal element in the remaining portion was measured by an X-ray fluorescence spectrometer (manufacturer: Rigaku, model: ZSX Primus III+) (inorganic particle weight M2 was calculated). 10 samples were taken for testing, and the final results were averaged.

(6) Reflectivity of visible light

According to the standards and terms in GB/T3291.2 and GB/T3291.3, the fibers are made into undyed fabrics, and the fabrics are cut into square pieces of 5cm*5cm using an integrating sphere photometer. In the case of no defects, face the light source away from the skin when wearing the fabric, measure its reflectance and record the reflectance R1 at a wavelength of 550 nm;

If it is necessary to test the reflectivity under liquid immersion, immerse the sample in tertiary water, adjust the moisture content of the sample to 100% (the mass after water immersion is 2 times before immersion). Wear the fabric away from the skin facing the light source, measure its reflectance and record the reflectance R2 at a wavelength of 550 nm;

Difference in reflectivity between wet and dry states = |R1-R2|.

10 samples were taken for testing, and the final results were averaged.

(7) Judgment of discoloration in wet and dry state

With reference to JIS L 0804:2005 Discoloration, Gray Card Judgment Standard, the fabrics in dry and wet state (liquid is not limited to water) are judged and rated for color. 10 samples were taken for testing, and the final results were averaged. Grade 4: No obvious discoloration ○; Grade 3-4: Slight discoloration △; Grade 3 and below: Obvious discoloration ×.

(8) Strength and elongation product of fiber

According to the standard GB/T14344-2008, the strength and elongation of the fiber were tested respectively, and the product of the fiber's strength and elongation was calculated using the following formula:

Strength-stretch product=strength×(stretch) ^1/2 .

10 samples were taken for testing, and the final results were averaged.

(9) Light fastness

According to the standard JIS L0842, the light fastness test is carried out for 20 hours, and the sample after irradiation treatment is compared with the unirradiated control sample, and judged according to the standard contrast gray card to determine the light fastness level. 10 samples were taken for testing, and the final results were averaged. The light fastness grade 4 and above was judged as ○, and the light fastness grade 3 and below was judged as △.

(10) Rutile Titanium Dioxide

The obtained fiber is melted to obtain a film, and the crystallization peak position is tested using an X-ray diffraction device, and the crystalline peak position of the usual rutile titanium dioxide is tested at the same time, and the crystal form of the titanium dioxide is judged by comparing the obtained crystalline peak positions.

(11) Spinning property

Count the floating and broken yarns in the spinning process. When the number of floating and broken yarns is less than 1 time/t, the spinnability is judged to be 0; when the number of floating and broken yarns is greater than 1 time/t, the spinning The sex judgment is ×.

The present invention will be described in detail below with reference to the embodiments.

Example 1

50 parts by weight of polyethylene terephthalate (PET) (polymer A) containing 15.0 wt % of rutile-type _TiO particles and 50 parts by weight of semi-matte polyester (polymerized) containing 0.3 wt % of _TiO particles were combined. Material B) were pre-crystallized, dried to below 50 ppm, respectively put into spinning A and B bins for spinning and false twisting to obtain long fibers with high permeability resistance. The cross-section of the fiber is a multi-layer concentric circle structure, the number of layers is 3, and the polymer B is in the outermost layer, and the outermost layer area accounts for 20% of the overall cross-sectional area. The strength and elongation product of the raw yarn is 17.3, and the obtained fiber is made into a tubular knitted fabric. The obtained tubular knitted fabric has an anti-penetration property of 94.8%, a difference of 550 nm dry and wet reflectance of 1.2%, and has anti-ultraviolet performance and light fastness. qualified.

Example 2

50 parts by weight of polyethylene terephthalate (PET) (polymer A) containing 15.0 wt % of rutile-type _TiO particles and 50 parts by weight of semi-matte polyester (polymerized) containing 0.3 wt % of _TiO particles were combined. Material B) were pre-crystallized, dried to below 50 ppm, respectively put into spinning A and B bins for spinning and false twisting to obtain long fibers with high permeability resistance. The cross-section of the fiber is a multi-layer concentric circle structure, the number of layers is 3, and the polymer B is in the outermost layer, and the outermost layer area accounts for 30% of the overall cross-sectional area. The strength and elongation product of the raw yarn is 17.5, and the obtained fiber is made into a tubular knitted fabric. The obtained tubular knitted fabric has an anti-penetration property of 94.1%, a difference of 550 nm dry and wet reflectance of 2.3%, and has anti-ultraviolet performance and light fastness. qualified.

Example 3

50 parts by weight of polyethylene terephthalate (PET) (polymer A) containing 15.0 wt % of rutile-type _TiO particles and 50 parts by weight of semi-matte polyester (polymerized) containing 0.3 wt % of _TiO particles were combined. Material B) were pre-crystallized, dried to below 50 ppm, respectively put into spinning A and B bins for spinning and false twisting to obtain long fibers with high permeability resistance. The cross section of the fiber is a multi-layer concentric circle structure, the number of layers is 3 layers, the polymer B is in the outermost layer, and the outermost layer area accounts for 10% of the overall area of the cross section, and the tensile and elongation area of the fiber is 17.7. The cylindrical knitted fabric is made, and the obtained tubular knitted fabric has an anti-penetration performance of 94.9%, a difference of 550 nm dry and wet reflectivity of 1.1%, and has anti-ultraviolet performance and qualified light fastness.

Example 4

60 parts by weight of polyethylene terephthalate (PET) (polymer A) containing 15.0 wt % of rutile-type _TiO particles and 40 parts by weight of semi-matte polyester (polymerized) containing 0.3 wt % of _TiO particles were combined. Material B) were pre-crystallized, dried to below 50 ppm, respectively put into spinning A and B bins for spinning and false twisting to obtain long fibers with high permeability resistance. The cross-section of the fiber is a multi-layer concentric circle structure, the number of layers is 3, and the polymer B is in the outermost layer, and the outermost layer area accounts for 20% of the overall cross-sectional area. The strength and elongation product of the raw yarn is 16.3, and the obtained fiber is made into a tube knitted fabric. The obtained tube knitted fabric has an anti-penetration property of 95.1%, a difference of 550 nm dry and wet reflectance of 0.9%, and has anti-ultraviolet performance and light fastness. qualified.

Example 5

70 parts by weight of polyethylene terephthalate (PET) (polymer A) containing 15.0 wt % of rutile-type _TiO particles and 30 parts by weight of semi-matte polyester (polymerized) containing 0.3 wt % of _TiO particles were combined. Material B) were pre-crystallized, dried to below 50 ppm, respectively put into spinning A and B bins for spinning and false twisting to obtain long fibers with high permeability resistance. The cross-section of the fiber is a multi-layer concentric circle structure, the number of layers is 3, and the polymer B is in the outermost layer, and the outermost layer area accounts for 20% of the overall cross-sectional area. The strength and elongation product of the raw yarn is 15.5, and the obtained fiber is made into a tubular fabric. The obtained tubular fabric has an anti-penetration property of 95.3%, a difference of 550 nm dry and wet reflectance of 0.8%, and has anti-ultraviolet performance and light fastness. qualified.

Example 6

30 parts by weight of polyethylene terephthalate (PET) (polymer A) containing 30.0 wt % of rutile-type TiO particles and 70 parts by weight of semi-matte polyester (polymer B) containing 0.3 wt % of TiO particles ) were pre-crystallized and dried to below 50ppm, respectively put into spinning A and B bins for spinning and false twisting to obtain long fibers with high permeability resistance. The cross-section of the fiber is a multi-layer concentric circle structure, the number of layers is 3, and the polymer B is in the outermost layer, and the outermost layer area accounts for 20% of the overall cross-sectional area. The strength and elongation product of the raw yarn is 17.5, and the obtained fiber is made into a tubular fabric. The obtained tubular fabric has an anti-penetration property of 95.4%, a difference of 550 nm dry and wet reflectance of 0.7%, and has anti-ultraviolet performance and light fastness. qualified.

Example 7

20 parts by weight of polyethylene terephthalate (PET) (polymer A) containing 60.0 wt % of rutile-type _TiO particles and 80 parts by weight of semi-matte polyester (polymerized) containing 0.3 wt % of _TiO particles Material B) were pre-crystallized, dried to below 50 ppm, respectively put into spinning A and B bins for spinning and false twisting to obtain long fibers with high permeability resistance. The cross section of the fiber is a multi-layer concentric circle structure, the number of layers is 3, and the polymer B is in the outermost layer, and the outermost layer area accounts for 20% of the overall area of the section. The strength and elongation product of the raw yarn is 19.1, and the obtained fiber is made into a tubular fabric. The obtained tubular fabric has an anti-penetration performance of 96.3%, a difference of 550 nm dry and wet reflectivity of 0.4%, and has anti-ultraviolet performance and light fastness. qualified.

Example 8

50 parts by weight of nylon 6 (N6) (polymer A) containing 15.0 wt % of rutile _TiO particles and 50 parts by weight of semi-dull nylon 6 (polymer B) containing 0.3 wt % of _TiO particles were pre-crystallized, respectively. Dry to below 50ppm, put into spinning A and B bins for spinning and false twisting to obtain long fibers with high anti-penetration performance. The cross-section of the fiber is a multi-layer concentric circle structure, the number of layers is 3, and the polymer B is in the outermost layer, and the outermost layer area accounts for 20% of the overall cross-sectional area. The strength and elongation product of the raw yarn is 21.5, and the obtained fiber is made into a tubular fabric. The obtained tubular fabric has an anti-penetration performance of 94.3%, a difference of 550 nm dry and wet reflectivity of 1.4%, and has anti-ultraviolet performance and light fastness. qualified.

Example 9

50 parts by weight of polypropylene (PP) containing 15.0 wt % of rutile _TiO particles (polymer A) and 50 parts by weight of polypropylene (PP) containing 0.3 wt % of _TiO particles (polymer B) were dried to 50ppm or less, put it into spinning A and B bins respectively for spinning and false twisting to obtain long fibers with high anti-penetration performance. The cross-section of the fiber is a multi-layer concentric circle structure, the number of layers is 3, and the polymer B is in the outermost layer, and the outermost layer area accounts for 20% of the overall cross-sectional area. The strength and elongation product of the raw yarn is 21.6, and the obtained fiber is made into a tubular knitted fabric. The obtained tubular knitted fabric has an anti-penetration performance of 94.3%, a difference of 550 nm dry and wet reflectivity of 1.5%, and has anti-ultraviolet performance and light fastness. qualified.

Example 10

50 parts by weight of polyethylene terephthalate (PET) containing 15.0 wt % of rutile _TiO particles (polymer A) and 50 parts by weight of semi-matte polyester (polymerized) containing 2.7 wt % of _TiO particles were combined. Material B) were pre-crystallized, dried to below 50 ppm, respectively put into spinning A and B bins for spinning and false twisting to obtain long fibers with high permeability resistance. The cross-section of the fiber is a multi-layer concentric circle structure, the number of layers is 3, and the polymer B is in the outermost layer, and the outermost layer area accounts for 20% of the overall cross-sectional area. The strength and elongation product of the raw yarn is 15.2, and the obtained fiber is made into a tubular fabric. The obtained tubular fabric has an anti-penetration performance of 94.6%, a difference of 550 nm dry and wet reflectance of 1.1%, and has anti-ultraviolet performance and light fastness. qualified.

Example 11

50 parts by weight of polyethylene terephthalate (PET) (polymer A) containing 15.0 wt % of rutile-type _TiO particles and 50 parts by weight of semi-matte polyester (polymerized) containing 5.0 wt % of _TiO particles Material B) were pre-crystallized, dried to below 50 ppm, respectively put into spinning A and B bins for spinning and false twisting to obtain long fibers with high permeability resistance. The cross-section of the fiber is a multi-layer concentric circle structure, the number of layers is 3, and the polymer B is in the outermost layer, and the outermost layer area accounts for 20% of the overall cross-sectional area. The strength and elongation product of the raw yarn is 15.0, and the obtained fiber is made into a tubular knitted fabric. The obtained tubular knitted fabric has an anti-penetration property of 94.9%, a difference of 550 nm dry and wet reflectance of 1.0%, and has anti-ultraviolet performance and light fastness. qualified.

Example 12

50 parts by weight of polyethylene terephthalate (PET) containing 15.0 wt % of zinc oxide particles (polymer A) and 50 parts by weight of semi-matte polyester (polymer B) containing 0.3 wt % of _TiO particles ) were pre-crystallized and dried to below 50ppm, respectively put into spinning A and B bins for spinning and false twisting to obtain long fibers with high permeability resistance. The cross-section of the fiber is a multi-layer concentric circle structure, the number of layers is 3, and the polymer B is in the outermost layer, and the outermost layer area accounts for 20% of the overall cross-sectional area. The strength and elongation product of the raw yarn is 15.6, and the obtained fiber is made into a tubular fabric. The obtained tubular fabric has an anti-penetration performance of 94.2%, a difference of 550 nm dry and wet reflectance of 3.2%, and has anti-ultraviolet performance and light fastness. qualified.

Example 13

50 parts by weight of polyethylene terephthalate (PET) (polymer A) containing 15.0 wt % of rutile-type _TiO particles and 50 parts by weight of semi-matte polyester (polymerized) containing 0.3 wt % of _TiO particles were combined. Material B) were pre-crystallized, dried to below 50 ppm, respectively put into spinning A and B bins for spinning and false twisting to obtain long fibers with high permeability resistance. The cross section of the fiber is a multi-layer concentric circle structure, the number of layers is 5, and the polymer B is in the outermost layer, and the outermost layer area accounts for 20% of the overall area of the section. The strength and elongation product of the raw yarn is 18.5, and the obtained fiber is made into a tubular fabric. The obtained tubular fabric has an anti-penetration performance of 94.4%, a difference of 550 nm dry and wet reflectivity of 1.4%, and has anti-ultraviolet performance and light fastness. qualified.

Example 14

50 parts by weight of polyethylene terephthalate (PET) (polymer A) containing 15.0 wt % of rutile-type _TiO particles and 50 parts by weight of semi-matte polyester (polymerized) containing 0.3 wt % of _TiO particles were combined. Material B) were pre-crystallized, dried to below 50 ppm, respectively put into spinning A and B bins for spinning and false twisting to obtain long fibers with high permeability resistance. The cross section of the fiber is a multi-layer concentric circle structure, the number of layers is 9, and the polymer B is in the outermost layer, and the outermost layer area accounts for 20% of the entire section area. The strength and elongation product of the raw yarn is 19.2, and the obtained fiber is made into a tubular knitted fabric. The obtained tubular knitted fabric has an anti-penetration performance of 94.2%, a difference of 550 nm dry and wet reflectivity of 1.8%, and has anti-ultraviolet performance and light fastness. qualified.

Example 15

45 parts by weight of polyethylene terephthalate (PET) (polymer A) containing 30.0 wt % of rutile-type _TiO particles, 45 parts by weight of semi-matte polyester (polymerized) containing 0.3 wt % of _TiO particles Compound B) and 10 parts by weight of polymer C containing 0.1 wt% antibacterial particles were pre-crystallized, dried to below 50 ppm, respectively put into spinning silos for spinning and false twisting to obtain long fibers with high permeability resistance. The cross section of the fiber is multi-layered, the number of layers is 3, the polymer C is in the innermost layer, the polymer A is in the middle layer, and the polymer B is in the outermost layer, and the outermost layer area accounts for 20% of the overall cross-sectional area. The product of wire strength and elongation is 15.1, and the obtained fiber is made into a tubular fabric. The obtained tubular fabric has an anti-penetration performance of 95.8%, and a difference of 550 nm dry and wet reflectivity of 0.7%. It has UV resistance and excellent performance. Antibacterial properties and light fastness are qualified.

Example 16

50 parts by weight of polyethylene terephthalate (PET) (polymer A) containing 15.0 wt % of anatase _TiO particles and 50 parts by weight of semi-matte polyester (polymer A) containing 0.3 wt % of _TiO particles Polymer B) is pre-crystallized, dried to below 50 ppm, and put into spinning A and B bins for spinning and false twisting to obtain long fibers with high permeability resistance. The cross-section of the fiber is a multi-layer concentric circle structure, the number of layers is 3, and the polymer B is in the outermost layer, and the outermost layer area accounts for 20% of the overall cross-sectional area. The strength and elongation product of the raw yarn is 17.5, and the obtained fiber is made into a tubular fabric. The obtained tubular fabric has an anti-penetration property of 94.4%, a difference of 550 nm dry and wet reflectivity of 1.4%, and has anti-ultraviolet performance and light fastness. qualified.

Example 17

50 parts by weight of polyethylene terephthalate (PET) (polymer A) containing 15.0 wt % of rutile-type _TiO particles and 50 parts by weight of semi-matte polyester (polymerized) containing 0.3 wt % of _TiO particles were combined. Material B) were pre-crystallized, dried to below 50 ppm, respectively put into spinning A and B bins for spinning and false twisting to obtain long fibers with high permeability resistance. The cross section of the fiber is a multi-layer hollow concentric circle structure, the number of layers is 3, and the polymer B is in the outermost layer, and the outermost layer area accounts for 20% of the overall section area. The strength and elongation product of the raw yarn is 16.2, and the obtained fiber is made into a tubular fabric. The obtained tubular fabric has an anti-penetration property of 94.4%, a difference of 550 nm dry and wet reflectivity of 1.8%, and has anti-ultraviolet performance and light fastness. qualified.

Example 18

70 parts by weight of polyethylene terephthalate (PET) (polymer A) containing 10.0 wt % of rutile-type _TiO particles and 30 parts by weight of semi-matte polyester (polymerized) containing 0.3 wt % of _TiO particles were combined. Material B) were pre-crystallized, dried to below 50 ppm, respectively put into spinning A and B bins for spinning and false twisting to obtain long fibers with high permeability resistance. The cross section of the fiber is a multi-layer concentric circle structure, the number of layers is 3, and the polymer B is in the outermost layer, and the outermost layer area accounts for 20% of the overall area of the section. The strength and elongation product of the raw yarn is 15.1, and the obtained fiber is made into a tubular fabric. The obtained tubular fabric has an anti-penetration performance of 94.1%, a 550 nm dry and wet reflectance difference of 2.7%, and has anti-ultraviolet performance and light fastness. qualified.

Example 19

10 parts by weight of polyethylene terephthalate (PET) (polymer A) containing 70.0 wt % of rutile-type _TiO particles and 90 parts by weight of semi-matte polyester (polymerized) containing 0.3 wt % of _TiO particles were combined. Material B) were pre-crystallized, dried to below 50 ppm, respectively put into spinning A and B bins for spinning and false twisting to obtain long fibers with high permeability resistance. The cross-section of the fiber is a multi-layer concentric circle structure, the number of layers is 3, and the polymer B is in the outermost layer, and the outermost layer area accounts for 20% of the overall cross-sectional area. The strength and elongation product of the raw yarn is 19.7, and the obtained fiber is made into a tube knitted fabric. The obtained tube knitted fabric has an anti-penetration performance of 94.8%, a difference of 550 nm dry and wet reflectance of 1.9%, and has anti-ultraviolet performance and light fastness. qualified.

Example 20

50 parts by weight of polyethylene terephthalate (PET) (polymer A) containing 15.0 wt % of rutile-type _TiO particles and 50 parts by weight of semi-matte polyester (polymerized) containing 0.3 wt % of _TiO particles were combined. Material B) were pre-crystallized, dried to below 50 ppm, respectively put into spinning A and B bins for spinning and false twisting to obtain long fibers with high permeability resistance. The cross section of the fiber is a multi-layer concentric circle structure with 15 layers, wherein the polymer B is in the outermost layer, and the area of the outermost layer accounts for 20% of the overall area of the section. The strength and elongation product of the raw yarn is 17.1, and the obtained fiber is made into a tubular fabric. The obtained tubular fabric has an anti-penetration performance of 94.0%, a difference of 550 nm dry and wet reflectance of 2.8%, and has anti-ultraviolet performance and light fastness. qualified.

Example 21

20 parts by weight of polyethylene terephthalate (PET) (polymer A) containing 60.0 wt % of rutile _TiO particles and 80 parts by weight of semi-matte polyester (polymerized) containing 0.3 wt % of _TiO particles were combined. Material B) were pre-crystallized, dried to below 50 ppm, respectively put into spinning A and B bins for spinning and false twisting to obtain long fibers with high permeability resistance. The cross section of the fiber is a multi-layer concentric circle structure, the number of layers is 3, and the number of layers is 3, wherein the polymer B is in the outermost layer, and the outermost layer area accounts for 40% of the overall area of the section. The strength and elongation product of the raw yarn is 19.2, and the obtained fiber is made into a tubular knitted fabric. The obtained tubular knitted fabric has an anti-penetration performance of 94.3%, a difference of 550 nm dry and wet reflectance of 1.8%, and has anti-ultraviolet performance and light fastness. qualified.

Example 22

50 parts by weight of polyethylene terephthalate (PET) (polymer A) containing 15.0 wt % of rutile-type _TiO particles and 50 parts by weight of semi-matte polyester (polymerized) containing 0.3 wt % of _TiO particles were combined. Material B) were pre-crystallized, dried to below 50 ppm, respectively put into spinning A and B bins for spinning and false twisting to obtain long fibers with high permeability resistance. The cross section of the fiber is a multi-layer concentric circle structure, the number of layers is 3, and the polymer B is in the outermost layer, and the outermost layer area accounts for 3% of the overall cross-sectional area. The strength and elongation product of the raw yarn is 17.1, and the obtained fiber is made into a tubular knitted fabric. The obtained tubular knitted fabric has an anti-penetration property of 95.0%, a difference of 550 nm dry and wet reflectance of 1.0%, and has anti-ultraviolet performance and light fastness. qualified.

Example 23

50 parts by weight of polyethylene terephthalate (PET) (polymer A) containing 70.0 wt % of rutile-type _TiO particles and 50 parts by weight of semi-matte polyester (polymerized) containing 0.3 wt % of _TiO particles were combined. Material B) were pre-crystallized, dried to below 50 ppm, respectively put into spinning A and B bins for spinning and false twisting to obtain long fibers with high permeability resistance. The cross-section of the fiber is a multi-layer concentric circle structure, the number of layers is 3, and the polymer B is in the outermost layer, and the outermost layer area accounts for 20% of the overall cross-sectional area. The strength and elongation product of the raw yarn is 15.0, and the obtained fiber is made into a tubular knitted fabric. The obtained tubular knitted fabric has an anti-penetration property of 97.3%, a difference of 550 nm dry and wet reflectance of 0.2%, and has anti-ultraviolet performance and light fastness. qualified.

Comparative Example 1

70 parts by weight of polyethylene terephthalate (PET) (polymer A) containing 7.5 wt % of rutile-type _TiO particles and 30 parts by weight of semi-matte polyester (polymerized) containing 0.3 wt % of _TiO particles were combined. Material B) were pre-crystallized, dried to below 50 ppm, respectively put into spinning A and B bins for spinning and false twisting to obtain long fibers with high permeability resistance. The cross section of the fiber is a multi-layer concentric circle structure, the number of layers is 3 layers, the polymer B is in the outermost layer, and the outermost layer area accounts for 20% of the overall area of the cross section, and the strength and elongation area of the original fiber is 15.3. The cylindrical knitted fabric was made, the anti-penetration performance of the obtained tubular knitted fabric was 86.9%, the difference of 550nm dry-wet reflectivity was 6.3%, it did not have anti-ultraviolet performance, the color changed obviously after being soaked in water, and the light fastness was qualified. When the content of inorganic particles in polymer A is less than 10.0 wt%, even if the content of polymer A in the composite fiber reaches 70 wt%, the anti-penetration effect of the composite fiber is not good, and the obtained fabric has poor UV resistance and dry-wet fading .

Comparative Example 2

45 parts by weight of polyethylene terephthalate (PET) (polymer A) containing 30.0 wt % of rutile-type _TiO particles, 45 parts by weight of semi-matte polyester (polymerized) containing 0.3 wt % of _TiO particles Compound B) and 10 parts by weight of polymer C containing 0.07wt% TiO ₂ particles were pre-crystallized, dried to below 50 ppm, respectively put into spinning silos for spinning and false twisting to obtain long fibers with high permeability resistance. The cross-section of the fiber is multi-layered, the number of layers is 3, the polymer A is in the innermost layer, the polymer B is in the middle layer, and the polymer C is in the outermost layer, and the outermost layer area accounts for 10% of the overall cross-sectional area. The product of wire strength and elongation is 16.4, and the obtained fiber is made into a tubular fabric. The obtained tubular fabric has an anti-penetration performance of 90.8%, a difference of 5.9% in dry and wet reflectivity at 550 nm, and does not have anti-ultraviolet performance. The discoloration is obvious, and the light fastness is qualified. Although it is also a three-layer cross-sectional structure, it is no different from the usual core-sheath fiber, and the polymer A with the highest inorganic particle content is placed in the innermost layer of the fiber. Compared with Example 15 with the same inorganic particle content, the fiber's permeability resistance Not good, the fabric has poor anti-ultraviolet and dry-wet discoloration fading effect.

Comparative Example 3

8 parts by weight of polyethylene terephthalate (PET) (polymer A) containing 70 wt % of rutile _TiO particles and 92 parts by weight of semi-matte polyester (polymer A) containing 0.3 wt % of _TiO particles were combined. B) Respectively pre-crystallize, dry to below 50ppm, put into spinning A and B bins respectively, spin and false twist to obtain long fibers with high permeability resistance. The cross-section of the fiber is a multi-layer concentric circle structure, the number of layers is 3, and the polymer B is in the outermost layer, and the outermost layer area accounts for 20% of the overall cross-sectional area. The strength and elongation product of the raw yarn is 19.9, and the obtained fiber is made into a tubular fabric. The obtained tubular fabric has an anti-penetration performance of 86.4%, a difference of 550 nm dry and wet reflectivity of 12.4%, has no anti-ultraviolet performance, and is wetted by water. After discoloration is obvious, the light fastness is qualified. When the content of polymer A in the composite fiber is less than 10%, even if the content of inorganic particles in polymer A reaches 70.0wt%, the anti-penetration effect of the composite fiber is not good, and the obtained fabric has poor UV resistance and dry-wet fading.

Comparative Example 4

50 parts by weight of polyethylene terephthalate (PET) (polymer A) containing 15 wt % of rutile _TiO particles and 50 parts by weight of semi-matte polyester (polymer A) containing 5.5 wt % of _TiO particles were combined. B) Respectively pre-crystallize, dry to below 50ppm, put into spinning A and B bins respectively for spinning, and the yarn breaks and floats during spinning. In addition, when the obtained POY is subjected to false twisting, yarn breakage occurs, and a large amount of white powder is generated when passing through the yarn guide, so that it cannot be crimped for a long time. False twisting produces long fibers with high anti-permeability. The cross section of the fiber is a multi-layer concentric circle structure with 3 layers, wherein the polymer B is in the outermost layer, and the outermost layer area accounts for 20% of the overall section area. The strength and elongation product of the raw yarn is 13.7, and the obtained fiber is made into a tubular fabric. The obtained tubular fabric has an anti-penetration performance of 94.4%, a difference of 550 nm dry and wet reflectivity of 1.2%, and has anti-ultraviolet performance. The discoloration is not obvious, and the light fastness is qualified. When the content of inorganic particles in the outermost polymer B is more than 5.0 wt %, the spinning process is seriously interrupted and the spinnability is poor.

Comparative Example 5

50 parts by weight of polyethylene terephthalate (PET) containing 15 wt % of rutile _TiO particles (polymer A) and 50 parts by weight of semi-matte polyester (polymer A) containing 0.3 wt % of _TiO particles B) Respectively pre-crystallize, dry to below 50ppm, put into spinning A and B bins respectively, spin and false twist to obtain long fibers with high permeability resistance. The cross section of the fiber is a multi-layer concentric circle structure, the number of layers is 20, and the polymer B is in the outermost layer, and the outermost layer area accounts for 20% of the overall area of the section. The obtained fiber has an abnormal cross-section, and the tensile and elongation product of the raw fiber is 15.4. The obtained fiber is made into a tubular knitted fabric, and the obtained tubular knitted fabric has an anti-penetration performance of 86.4%, and a difference of 550 nm dry and wet reflectance of 9.4%. It has anti-ultraviolet performance, obvious discoloration after being soaked in water, and the light fastness is qualified. Due to too many layers, the forming of the fiber section is abnormal, and the anti-penetration, anti-ultraviolet, dry and wet fading effect is not good.

Comparative Example 6

10 parts by weight of polyethylene terephthalate (PET) (polymer A) containing 80 wt % of rutile-type _TiO particles and 70 parts by weight of semi-matte polyester (polymer A) containing 0.3 wt % of _TiO particles B) Respectively pre-crystallize, dry to below 50ppm, put into spinning A and B bins respectively, spin and false twist to obtain long fibers with high permeability resistance. The cross-section of the fiber is a multi-layer concentric circle structure, the number of layers is 3, and the polymer B is in the outermost layer, and the outermost layer area accounts for 20% of the overall cross-sectional area. During the spinning process, due to the poor fluidity of the polymer A, the cross-section was abnormally compounded, and the filaments were broken during the spinning, and the filaments were floating. In addition, when the obtained POY is subjected to false twisting, yarn breakage occurs, and a large amount of white powder is generated when passing through the yarn guide, so that it cannot be crimped for a long time. The strength and elongation product of the raw yarn is 17.2, and the obtained fiber is made into a tube knitted fabric. The obtained tube knitted fabric has an anti-penetration performance of 95.9%, a difference of 550 nm dry and wet reflectivity of 0.6%, and has anti-ultraviolet performance. There is no obvious discoloration, and the light fastness is qualified. When the content of inorganic particles in polymer A is higher than 70.0 wt%, the spinning process is seriously interrupted and the spinnability is poor.

Comparative Example 7

75 parts by weight of polyethylene terephthalate (PET) (polymer A) containing 10 wt % of rutile TiO2 particles and 25 parts by weight of semi-matte polyester (polymer B) containing 0.3 wt % of TiO2 particles Pre-crystallized and dried to below 50ppm, respectively put into spinning A and B bins for spinning and false twisting to obtain long fibers with high anti-permeability performance. The cross-section of the fiber is a multi-layer concentric circle structure, the number of layers is 3, and the polymer B is in the outermost layer, and the outermost layer area accounts for 20% of the overall cross-sectional area. The fiber strength and elongation product is 12.7. During the spinning process, because the fiber strength and elongation product is too small, the broken silk appears. In addition, poor workability and wire breakage also occur during processing. The obtained fiber is made into a tubular knitted fabric, and the obtained tubular knitted fabric has an anti-penetration property of 94.9%, a 550-nm dry-wet reflectance difference of 1.2%, and has anti-ultraviolet performance and qualified light fastness. When the content of polymer A in the composite fiber is higher than 70%, the strength and elongation product of the fiber is small and cannot meet the requirements of normal use.

Claims (10)

1. A multi-layer cross-sectional composite fiber, characterized in that: the cross-section of the fiber has a multi-layer cross-sectional structure of 3 to 15 layers formed by alternately arranging at least two components, and the outermost layer of the multi-layer cross-sectional structure is composed of inorganic particles. The content of polymer B is 5.0 wt % or less, and at least one layer of the composite fiber is formed of polymer A with an inorganic particle content of 10.0-70.0 wt %, and the polymer A accounts for 10-70 wt % of the composite fiber.
2. The multi-layer cross-section composite fiber according to claim 1, wherein the content of the inorganic particles derived from the polymer A in the composite fiber is 7.0 to 30.0 wt %.
3. The multi-layer cross-section composite fiber according to claim 1 or 2 is characterized in that: the cross-section of the fiber has a cross-sectional structure of 3 to 9 layers formed by alternately arranging polymer A and polymer B.
4. The multi-layer cross-section composite fiber according to claim 1 or 2, wherein the content of inorganic particles in the polymer-free A is 15-60 wt%.
5. The multi-layer cross-sectional composite fiber according to claim 1 or 2, wherein the outermost layer area of the multi-layer cross-sectional structure accounts for 5-30% of the overall cross-sectional area.
6. The multi-layer cross-section composite fiber according to claim 1 or 2, wherein the polymer is polyester, nylon, polypropylene or polyurethane.
7. The multi-layer cross-section composite fiber according to claim 1 or 2, wherein the absolute value of the difference in the reflectivity of visible light with a wavelength of 550 nanometers in the dry and wet state of the composite fiber is less than 5.0%.
8. The multi-layer cross-section composite fiber according to claim 1 or 2, characterized in that: the strength-elongation product of the composite fiber is above 15.0.
9. A kind of fabric is obtained by the preparation of the multi-layer section composite fiber according to claim 1.
10. The fabric according to claim 9, wherein the absolute value of the difference in the visible light reflectance of the fabric in the wet and dry state at a wavelength of 550 nanometers is less than 5.0%.

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