Full-dull cross-shaped profiled fiber and preparation method thereof

Abstract

The invention discloses a full-dull cross-shaped profiled fiber, the raw materials of the cross-shaped profiled fiber comprise PET polyester and a delustering agent, and the delustering agent is aluminum-silicon double-layer coated titanium dioxide. Aluminum-silicon double-layer coated titanium dioxide is added into the cross-shaped profiled fiber, the aluminum-silicon double-layer coated titanium dioxide shields chemical active sites of the titanium dioxide, and thermal degradation of polyester in the preparation process of the titanium dioxide master batch is reduced. The invention also aims to disclose a preparation method of the full-dull cross-shaped profiled fiber, which comprises the following steps: preparing the PET polyester and the titanium dioxide master batch, melting the PET polyester and the titanium dioxide master batch to obtain a PET polyester melt, extruding the PET polyester melt from a spinneret orifice on a spinneret plate to obtain the full-dull cross-shaped profiled fiber. And the cross-shaped profiled fiber is prepared through an FDY spinning process. The preparation method disclosed by the invention is good in controllability, and the prepared cross-shaped profiled fiber can accelerate moisture absorption and sweat releasing and keep the interior dry and clean.

Description

Technical Field

[0001] The invention relates to the technical field of spinning production, in particular to a full-dull cross-shaped fiber and a preparation method thereof. Background Art

[0002] The surface gloss of general circular cross-section fibers is weak, waxy, and easy to get dirty, easy to pilling, not absorb water, and have poor coverage. After the fiber cross-section is profiled, the gloss, bulkiness, hygroscopicity, anti-pilling, pilling, stain resistance, stiffness, elasticity, and feel of the textiles can be improved to varying degrees. Imitation of silk, wool, linen, and animal fur can all be achieved through the physical properties of profiled fibers combined with other process conditions.

[0003] Since the surface of polyester fiber is smooth and transparent, the intensity of its reflected light is very high under visible light. This strong reflected light is commonly known as "aurora", which makes people's eyes look uncomfortable. In order to eliminate this uncomfortable reflected light, a small amount of substances with different refractive indices are added to the fiber to make the light diffusely reflect in different directions, and the luster of the fiber will become darker. The added substance is called a matting agent. Full matte polyester fiber has the characteristics of soft luster, good deep dyeing, high fabric drape, strong shielding performance, etc., and can be widely used in high-end casual clothing and wool-like fabrics.

[0004] However, as the titanium dioxide content increases, the viscosity of the polyester melt will decrease, which will have a greater impact on the fluidity of the polyester. Generally, titanium dioxide is added in the form of masterbatch. During the process of making the masterbatch, titanium dioxide will cause thermal degradation of the polyester, resulting in the inability to produce polyester fibers with good performance.

[0005] Moisture wicking fibers can regulate the microclimate inside clothing, instantly expel moisture and sweat from the body, and keep the skin dry and clean. Therefore, the demand for this fiber is very strong in sports, leisure and underwear products, demonstrating its economic, comfortable and functional product features.

[0006] Generally speaking, the coverage and fluffiness of shaped fibers are better than those of ordinary synthetic fibers. The fabrics made of shaped fibers are thicker, fluffier, fuller, lighter and more breathable. The more complex the cross section of the shaped fiber or the higher the degree of shaped fiber, the better the fluffiness and breathability of the fiber and fabric. How to further improve the degree of shaped fiber has always been a difficult problem in full matte products. Therefore, a new technical solution is urgently needed to solve at least one of the above technical problems. Summary of the invention

[0007] In view of the above shortcomings, one object of the present invention is to provide a fully matte cross-shaped fiber, in which the aluminum-silicon double-layer coating shields the chemical active points of titanium dioxide, thereby reducing the thermal degradation of polyester during the preparation of titanium dioxide masterbatch. Another object of the present invention is to disclose a method for preparing a fully matte cross-shaped fiber, which has good controllability, and the prepared cross-shaped fiber can accelerate moisture absorption and perspiration, and keep the interior dry and clean.

[0008] In order to achieve the above technical objectives and meet the above technical requirements, the technical solution adopted by the present invention is: A fully matte cross-shaped fiber, characterized in that the raw materials of the cross-shaped fiber include PET polyester and a matting agent, and the matting agent is titanium dioxide with an aluminum-silicon double-layer coating.

[0009] As a preferred technical solution, the content of the matting agent is 2.0-2.2wt%.

[0010] The present invention also provides a method for preparing a fully matte cross-shaped fiber, comprising the following steps: The PET polyester and titanium dioxide masterbatch are prepared, the PET polyester and titanium dioxide masterbatch are melted to obtain a PET polyester melt, the PET polyester melt is extruded from the spinneret holes on the spinneret, and the cross-shaped fiber is obtained through an FDY spinning process; The spinneret hole is cross-shaped, and includes a transverse flow channel and a vertical flow channel perpendicular to the transverse flow channel. The length ratio of the transverse flow channel to the vertical flow channel is 1:1. The intersection of the transverse flow channel and the vertical flow channel is the midpoint of the transverse flow channel. The transverse flow channel has the same width as the vertical flow channel. The length and width ratio of the vertical flow channel is (3.5-5.5):1.

[0011] As a preferred technical solution, the intrinsic viscosity of the PET polyester melt is 0.63-0.67 dL / g.

[0012] As a preferred technical solution, the specific steps of preparing the matting agent are: Weigh an appropriate amount of finely ground titanium dioxide, disperse it in deionized water to prepare a mass concentration of 20-25wt%, and add sodium hexametaphosphate to prepare a slurry, adjust the pH to 10-11, stir the slurry evenly, heat it to 80-85° C. and stir it, gradually drop 0.3 mol / L Na2SiO3·9H2O solution, wherein the mass of Na2SiO3 is 1.0-1.2% of titanium dioxide, and then gradually drop 1.6wt% H2SO4 to maintain the pH stable at pH=9.5, age it for 2-3h after the dropwise addition is completed, and then centrifuge, wash, dry and grind it to obtain silicon-coated titanium dioxide; The silicon-coated titanium dioxide is dispersed in deionized water to a mass concentration of 20-25wt%, and then a 0.6mol / L NaAlO2 solution is added dropwise, and 1.6wt% H2SO4 is added simultaneously to maintain the pH value at 9.0, wherein the mass of NaAlO2 is 2.5-3.0% of the titanium dioxide. After the addition is completed, the solution is aged for 2-3h, and then centrifuged, washed, dried, and ground to obtain aluminum-silicon double-layer coated titanium dioxide; Place the aluminum-silicon double-layer coated titanium dioxide in a dryer and introduce SO2 gas at a temperature of 100-120°C, a gas flow rate of 3-5m3 / h·kg, and a time of 2-3h; The titanium dioxide coated with aluminum silicon double layer, the bright polyester and the stabilizer are mixed in a weight percentage of (40-50): (60-50) to obtain a mixed powder, and the amount of the stabilizer added is 500-800ppm of the polyester mass; The mixed powder is dried at a temperature of 150-170°C for 12-15 hours, and the moisture content is controlled to be less than 30ppm. The dried mixed powder is fed into a twin-screw extruder for melt granulation at a twin-screw extruder temperature of 250-275°C to obtain titanium dioxide masterbatch.

[0013] As a preferred technical solution, the intrinsic viscosity of the titanium dioxide masterbatch is 0.45-0.48 dL / g.

[0014] As a preferred technical solution, the intrinsic viscosity of the high-gloss polyester is 0.64-0.67 dL / g.

[0015] As a preferred technical solution, the stabilizer is triphenyl phosphate.

[0016] As a preferred technical solution, the parameters of the FDY spinning process are: cooling temperature 20-25°C, first roller speed 2000-2200m / min, first roller temperature 75-85°C, second roller speed 2800-3000m / min, second roller temperature 130-140°C, and winding speed 2830-2920m / min.

[0017] As a preferred technical solution, the single fiber fineness of the cross-shaped fiber is 0.8-1.2 dtex, the breaking strength is ≥3.30 cN / dtex, the breaking elongation is 40±5.0%, the network degree is 15±4 pieces / m, the linear density deviation rate is ≤1.0%, the breaking strength CV value is ≤5.0%, the breaking elongation CV value is ≤10.0%, and the boiling water shrinkage is 7.5±0.5%.

[0018] Compared with the traditional technical solution, the beneficial effects of the present invention are: 1) Using titanium dioxide with aluminum-silicon double-layer coating, the chemically inert oxide film shields the chemically active points of titanium dioxide, reducing the thermal degradation of polyester during the preparation of titanium dioxide masterbatch; 2) The preparation method of full-dull cross-shaped fiber has good controllability. The prepared cross-shaped fiber can accelerate moisture absorption and perspiration, keep the interior dry and clean; 3) On the basis of the silicon oxide and aluminum oxide coating of titanium dioxide, SO2 gas is introduced to form the oxidation product SO4 2- Because it occupies the active center of the catalyst, it also reduces the percentage of titanium atoms on the surface of the coated titanium dioxide, causing the catalytic activity of titanium dioxide to gradually become inactive, further reducing the thermal degradation of polyester by titanium dioxide during the masterbatch processing, and thus preparing shaped fibers with better shape retention effect; 4) Adding a certain amount of stabilizer into the polymerization system can reduce the coordination ability of titanium in titanium dioxide to the carbonyl oxygen in polyester, inhibit the activity of titanium dioxide catalyst, and facilitate the processing and preparation of titanium dioxide masterbatch. DETAILED DESCRIPTION

[0019] An embodiment of the present invention provides a fully matte cross-shaped fiber, wherein the raw materials of the cross-shaped fiber include PET polyester and a matting agent, wherein the matting agent is titanium dioxide with an aluminum-silicon double-layer coating. The titanium dioxide with an aluminum-silicon double-layer coating is used, and the chemically inert oxide film layer shields the chemically active points of the titanium dioxide, thereby reducing the thermal degradation of the polyester during the preparation of the titanium dioxide masterbatch.

[0020] In some embodiments, the content of the matting agent is 2.0-2.2wt% of the entire raw material. If the matting agent is less than 2.0wt%, the matting effect is poor. If the matting agent is greater than 2.2wt%, the surface friction of the cross-shaped fiber is too large, resulting in broken fibers, floating fibers, and the like.

[0021] The present invention also provides a method for preparing a fully matte cross-shaped fiber, comprising the following steps: The PET polyester and titanium dioxide masterbatch are prepared, the PET polyester and titanium dioxide masterbatch are melted to obtain a PET polyester melt, the PET polyester melt is extruded from the spinneret holes on the spinneret, and the cross-shaped fiber is obtained through an FDY spinning process; The spinneret hole is cross-shaped, and the spinneret hole includes a transverse flow channel and a vertical flow channel perpendicular to the transverse flow channel. The length ratio of the transverse flow channel to the vertical flow channel is 1:1. The intersection of the transverse flow channel and the vertical flow channel is the midpoint of the transverse flow channel and the vertical flow channel. The width of the transverse flow channel is the same as that of the vertical flow channel. The length and width ratio of the vertical flow channel is (3.5-5.5):1. The PET polyester melt is extruded from the spinneret hole to form a highly shaped cross-shaped fiber. The cross-shaped fiber prepared in this way can accelerate moisture absorption and perspiration, and keep the interior dry and clean. Since the polymer melt will produce an outlet expansion effect during extrusion, if the aspect ratio is close, the cross shape will be unclear, which will reduce the moisture absorption and perspiration effect. More gaps will be formed between the cross-shaped fibers than round fibers, which will produce more capillary effects and accelerate moisture absorption and perspiration.

[0022] In some embodiments, the intrinsic viscosity of the PET polyester melt is 0.63-0.67 dL / g, and the fluidity is good.

[0023] In some embodiments, the specific steps of preparing the matting agent are: Weigh an appropriate amount of finely ground titanium dioxide, disperse it in deionized water to prepare a mass concentration of 20-25wt%, and add sodium hexametaphosphate to prepare a slurry, adjust the pH to 10-11, stir the slurry evenly, heat it to 80-85° C. and stir it, gradually drop 0.3 mol / L Na2SiO3·9H2O solution, wherein the mass of Na2SiO3 is 1.0-1.2% of the mass of titanium dioxide, and then gradually drop 1.6wt% H2SO4 to maintain the pH stable at pH=9.5, age it for 2-3h after the dropwise addition is completed, and then centrifuge, wash, dry and grind it to obtain silicon-coated titanium dioxide; The silicon-coated titanium dioxide is dispersed in deionized water to a mass concentration of 20-25wt%, and then a 0.6mol / L NaAlO2 solution is added dropwise, and 1.6wt% H2SO4 is added simultaneously to maintain the pH value at 9.0, wherein the mass of NaAlO2 is 2.5-3.0% of the titanium dioxide. After the addition is completed, the solution is aged for 2-3h, and then centrifuged, washed, dried, and ground to obtain aluminum-silicon double-layer coated titanium dioxide; Place the aluminum-silicon double-layer coated titanium dioxide in a dryer and introduce SO2 gas at a temperature of 100-120°C and a gas flow rate of 3-5m 3 / h·kg, time 2-3h; The titanium dioxide coated with aluminum silicon double layer, bright polyester and a stabilizer are mixed to obtain a mixed powder, wherein the weight percentage of titanium dioxide and bright polyester is (40-50): (60-50), and the amount of the stabilizer added is 500-800ppm of the mass of the bright polyester, and the stabilizer is triphenyl phosphate; The mixed powder is dried at a temperature of 150-170°C for 12-15 hours, and the moisture content is controlled to be less than 30ppm. The dried mixed powder is fed into a twin-screw extruder for melt granulation at a twin-screw extruder temperature of 250-275°C to obtain titanium dioxide masterbatch.

[0024] When using the FDY spinning process to prepare shaped fibers, it is generally impossible to achieve the ideal design effect. In addition to the extrusion expansion effect when the polyester melt passes through the spinneret, another factor is that the viscosity of the polyester melt containing the matting agent is relatively low, resulting in a relatively "round" fiber cross-section without edges and corners, and the shape retention effect of the shaped fiber is poor.

[0025] Titanium dioxide is a polycrystalline inorganic compound, which has tetragonal rutile type (R type) and anatase type (A type), as well as brookite type with properties between the two. Titanium dioxide is a wide bandgap semiconductor, and its valence band is formed by the hybridization of oxygen 2p orbital and iron 3d orbital. When the energy is greater than or equal to the bandgap width (Eg), titanium dioxide has a certain catalytic activity. At high temperatures, the electrons in the valence band of titanium dioxide are excited to jump to the empty conduction band, forming electron-hole pairs with strong redox. The electrons can be captured by O2 in the system to form free radicals O2·, and the holes can be oxidized to H2O to form free radicals HO·, O2· and HO·, which are very active and can cause thermal degradation of polyester macromolecules. Although the catalytic activity of titanium dioxide is not high, the content of titanium dioxide is as high as 50% when preparing titanium dioxide masterbatch, which makes the thermal degradation of polyester very serious. Usually, the intrinsic viscosity of titanium dioxide masterbatch is about 0.25-0.27dL / g, which is much lower than the melt viscosity of polyester. Usually, the titanium dioxide content in polyester semi-dull fiber is about 0.2-0.25%, while the titanium dioxide content in full-dull cross-shaped fiber is 2.0-2.5%. A large amount of low molecular weight bright polyester has a greater impact on fluidity. For full-dull products, since the titanium dioxide content is more than 7-8 times that of semi-dull products, titanium dioxide masterbatch is more likely to cause degradation during the spinning process. During the spinning process of full-dull fiber, the viscosity drop caused by titanium dioxide masterbatch is as high as 0.020-0.030dL / g, while the viscosity drop during semi-dull spinning is about 0.005-0.008dL / g.

[0026] Since titanium dioxide itself has lattice defects and is a wide bandgap semiconductor and is chemically active, a chemically inert oxide film layer can be coated on the surface of titanium dioxide to shield its chemically active points. The coating materials on the surface of titanium dioxide are silicon oxide and aluminum oxide, but the surface coating of silicon oxide and aluminum oxide still cannot completely cover the surface of titanium dioxide. In the prior art, the percentage of titanium atoms in the surface of titanium dioxide coated with silicon oxide and aluminum oxide is 13-18% (25-26% for uncoated). This is because when the amount of NaAlO2 added reaches a certain value, part of the NaAlO2 will crystallize, and the percentage of titanium atoms in the coated titanium dioxide surface cannot be further reduced.

[0027] The present invention is based on the double-layer coating of silicon oxide and aluminum oxide on titanium dioxide, and SO2 gas is introduced to form an oxidation product SO4 2- Because it occupies the active center of the catalyst, it also reduces the percentage of titanium atoms in the surface of the coated titanium dioxide, causing the catalyst to gradually become inactive, further reducing the thermal degradation of polyester by titanium dioxide during the masterbatch processing, and thus preparing cross-shaped fibers with good shape retention. A certain amount of stabilizer is added to the polymerization system to reduce the coordination ability of titanium in titanium dioxide to the carbonyl oxygen in polyester, which inhibits the activity of the catalyst and is beneficial to the preparation of titanium dioxide masterbatch.

[0028] In some embodiments, the intrinsic viscosity of the titanium dioxide masterbatch is 0.45-0.48 dL / g. When the intrinsic viscosity of the titanium dioxide masterbatch is lower than 0.45 dL / g or greater than 0.48 dL / g, the cross-shaped fiber forming effect is poor.

[0029] In some embodiments, the intrinsic viscosity of the bright polyester is 0.64-0.67 dL / g. When the intrinsic viscosity of the bright polyester is lower than 0.64 dL / g or higher than 0.67 dL / g, the cross-shaped fiber forming effect is poor.

[0030] In some embodiments, after the PET polyester melt is extruded from the spinneret holes on the spinneret, the FDY spinning process is cooling, stretching, and winding. The parameters of the FDY spinning process are: cooling temperature 20-25°C, first roller speed 2000-2200m / min, first roller temperature 75-85°C, second roller speed 2800-3000m / min, second roller temperature 130-140°C, winding speed 2830-2920m / min, cooling using ring blowing, and stretching between the first roller and the second roller.

[0031] In some embodiments, the single fiber fineness of the cross-shaped fiber is 0.8-1.2 dtex, the breaking strength is ≥3.30 cN / dtex, the breaking elongation is 40±5.0%, the network degree is 15±4 pieces / m, the linear density deviation rate is ≤1.0%, the breaking strength CV value is ≤5.0%, the breaking elongation CV value is ≤10.0%, and the boiling water shrinkage is 7.5±0.5%. Example

[0032] A fully matte cross-shaped fiber. The raw materials of the cross-shaped fiber include PET polyester and a matting agent. The matting agent is titanium dioxide with an aluminum-silicon double-layer coating. The content of the matting agent is 2.0wt%.

[0033] The present invention also provides a method for preparing a fully matte cross-shaped fiber, comprising the following steps: The PET polyester and titanium dioxide masterbatch are prepared, the PET polyester and titanium dioxide masterbatch are melted to obtain a PET polyester melt, the PET polyester melt is extruded from the spinneret holes on the spinneret, and the cross-shaped fiber is obtained through an FDY spinning process; The spinneret hole is cross-shaped, and includes a transverse flow channel and a vertical flow channel perpendicular to the transverse flow channel. The length ratio of the transverse flow channel to the vertical flow channel is 1:1. The intersection of the transverse flow channel and the vertical flow channel is the midpoint of the transverse flow channel and the vertical flow channel. The transverse flow channel has the same width as the vertical flow channel. The length to width ratio of the vertical flow channel is 5.5:1. The characteristic viscosity of the PET polyester melt is 0.63dL / g.

[0034] The specific steps of preparing the matting agent are: Weigh an appropriate amount of finely ground titanium dioxide, disperse it in deionized water to prepare a mass concentration of 20wt%, and add sodium hexametaphosphate to prepare a slurry, adjust the pH to 10, stir the slurry evenly, heat it to 80°C and stir it, gradually drop 0.3mol / L Na2SiO3·9H2O solution, wherein the mass of Na2SiO3 is 1.0% of the mass of titanium dioxide, and then gradually drop 1.6wt% H2SO4 to maintain the pH stable at pH=9.5. After the dropwise addition is completed, age for 2h, and then centrifuge, wash, dry, and grind to obtain silicon-coated titanium dioxide; The silicon-coated titanium dioxide is dispersed in deionized water to a mass concentration of 20wt%, and then a 0.6mol / L NaAlO2 solution is added dropwise, and 1.6wt% H2SO4 is added simultaneously to maintain the pH value at 9.0, wherein the mass of NaAlO2 is 2.5% of the titanium dioxide. After the addition is completed, the solution is aged for 2-3h, and then centrifuged, washed, dried, and ground to obtain aluminum-silicon double-layer coated titanium dioxide; The aluminum-silicon double-layer coated titanium dioxide was placed in a dryer and SO2 gas was introduced at a temperature of 100°C and a gas flow rate of 3m 3 / h·kg, time 2h; The titanium dioxide with aluminum-silicon double-layer coating, the bright polyester and the stabilizer are mixed in a weight percentage of 40:60 to obtain a mixed powder, and the amount of the stabilizer added is 500ppm of the mass of the bright polyester; The mixed powder is dried at a temperature of 150°C for 12 hours, and the moisture content is controlled to be less than 30ppm. The dried mixed powder is fed into a twin-screw for melt granulation at a temperature of 250°C to obtain a titanium dioxide masterbatch. The intrinsic viscosity of the titanium dioxide masterbatch is 0.45dL / g, and the intrinsic viscosity of the bright polyester is 0.64dL / g. The stabilizer is triphenyl phosphate.

[0035] The FDY spinning process includes cooling, stretching and winding. The parameters of the FDY spinning process are as follows: cooling temperature 20°C, first roller speed 2000m / min, first roller temperature 75°C, second roller speed 2800m / min, second roller temperature 130°C, winding speed 2830m / min, and stretching is performed between the first roller and the second roller.

[0036] The cross-shaped fiber has a single-filament fineness of 0.8 dtex, a breaking strength of 4 cN / dtex, an elongation at break of 35%, a network degree of 11 pieces / m, a linear density deviation rate of 0.7%, a breaking strength CV value of 4.1%, a breaking elongation CV value of 8.5%, a boiling water shrinkage rate of 7%, and a wicking height greater than 155 mm. Example

[0037] A fully matte cross-shaped fiber. The raw materials of the cross-shaped fiber include PET polyester and a matting agent. The matting agent is titanium dioxide with an aluminum-silicon double-layer coating. The content of the matting agent is 2.1wt%.

[0038] The present invention also provides a method for preparing a fully matte cross-shaped fiber, comprising the following steps: The PET polyester and titanium dioxide masterbatch are prepared, the PET polyester and titanium dioxide masterbatch are melted to obtain a PET polyester melt, the PET polyester melt is extruded from the spinneret holes on the spinneret, and the cross-shaped fiber is obtained through an FDY spinning process; The spinneret hole is cross-shaped, and includes a transverse flow channel and a vertical flow channel perpendicular to the transverse flow channel. The length ratio of the transverse flow channel to the vertical flow channel is 1:1. The intersection of the transverse flow channel and the vertical flow channel is the midpoint of the transverse flow channel and the vertical flow channel. The transverse flow channel has the same width as the vertical flow channel. The length to width ratio of the vertical flow channel is 3.5:1. The characteristic viscosity of the PET polyester melt is 0.65dL / g.

[0039] The specific steps of preparing the matting agent are: Weigh an appropriate amount of finely ground titanium dioxide, disperse it in deionized water to prepare a mass concentration of 23wt%, and add sodium hexametaphosphate to prepare a slurry, adjust the pH to 11, stir the slurry evenly, heat it to 82°C and stir it, gradually drop 0.3mol / L Na2SiO3·9H2O solution, wherein the mass of Na2SiO3 is 1.1% of the mass of titanium dioxide, and then gradually drop 1.6wt% H2SO4 to maintain the pH stable at pH=9.5. After the dropwise addition is completed, age for 2.5h, and then centrifuge, wash, dry, and grind to obtain silicon-coated titanium dioxide; The silicon-coated titanium dioxide was dispersed in deionized water to a mass concentration of 23wt%, and then a 0.6mol / L NaAlO2 solution was added dropwise, and 1.6wt% H2SO4 was added simultaneously to maintain the pH value at 9.0, wherein the mass of NaAlO2 was 2.7% of the titanium dioxide. After the addition was completed, the solution was aged for 2.5h, and then centrifuged, washed, dried, and ground to obtain aluminum-silicon double-layer coated titanium dioxide; The aluminum-silicon double-layer coated titanium dioxide was placed in a dryer and SO2 gas was introduced, where the temperature was 110°C and the gas flow rate was 4m 3 / h·kg, time 2.5h; The titanium dioxide with aluminum-silicon double-layer coating, the bright polyester and the stabilizer are mixed in a weight percentage of 45:55 to obtain a mixed powder, the stabilizer is added in an amount of 500-800ppm of the polyester mass, and the stabilizer is triphenyl phosphate; The mixed powder is dried at a temperature of 160°C for 13 hours, and the moisture content is controlled to be less than 30 ppm. The dried mixed powder is fed into a twin-screw for melt granulation at a temperature of 260°C to obtain a titanium dioxide masterbatch. The intrinsic viscosity of the titanium dioxide masterbatch is 0.46 dL / g, and the intrinsic viscosity of the high-gloss polyester is 0.65 dL / g.

[0040] The FDY spinning process includes cooling, stretching and winding. The parameters of the FDY spinning process are as follows: cooling temperature 23°C, first roller speed 2100m / min, first roller temperature 80°C, second roller speed 2900m / min, second roller temperature 135°C, winding speed 2900m / min, and stretching between the first roller and the second roller.

[0041] The cross-shaped fiber has a single-filament fineness of 1.1 dtex, a breaking strength of 4.27 cN / dtex, an elongation at break of 42%, a network density of 16 pieces / m, a linear density deviation rate of 0.9%, a breaking strength CV value of 4.2%, a breaking elongation CV value of 9.2%, a boiling water shrinkage rate of 7.8%, and a wicking height greater than 158 mm. Example

[0042] A fully matte cross-shaped fiber. The raw materials of the cross-shaped fiber include PET polyester and a matting agent. The matting agent is titanium dioxide with an aluminum-silicon double-layer coating. The content of the matting agent is 2.2wt%.

[0043] The present invention also provides a method for preparing a fully matte cross-shaped fiber, comprising the following steps: The PET polyester and titanium dioxide masterbatch are prepared, the PET polyester and titanium dioxide masterbatch are melted to obtain a PET polyester melt, the PET polyester melt is extruded from the spinneret holes on the spinneret, and the cross-shaped fiber is obtained through an FDY spinning process; The spinneret hole is cross-shaped, and includes a transverse flow channel and a vertical flow channel perpendicular to the transverse flow channel. The length ratio of the transverse flow channel to the vertical flow channel is 1:1. The intersection of the transverse flow channel and the vertical flow channel is the midpoint of the transverse flow channel and the vertical flow channel. The transverse flow channel has the same width as the vertical flow channel. The length to width ratio of the vertical flow channel is 4.5:1. The characteristic viscosity of the PET polyester melt is 0.67dL / g.

[0044] The specific steps of preparing the matting agent are: Weigh an appropriate amount of finely ground titanium dioxide, disperse it in deionized water to prepare a mass concentration of 25wt%, and add sodium hexametaphosphate to prepare a slurry, adjust the pH to 11, stir the slurry evenly, heat it to 85°C and stir it, gradually drop 0.3mol / L Na2SiO3·9H2O solution, wherein the mass of Na2SiO3 is 1.2% of titanium dioxide, and then gradually drop 1.6wt% H2SO4 to maintain the pH stable at pH=9.5, age for 3h after the dropwise addition, and then centrifuge, wash, dry and grind to obtain silicon-coated titanium dioxide; The silicon-coated titanium dioxide was dispersed in deionized water to a mass concentration of 25wt%, and then a 0.6mol / L NaAlO2 solution was added dropwise, and 1.6wt% H2SO4 was added simultaneously to maintain the pH value at 9.0. The mass of NaAlO2 was 3.0% of the titanium dioxide. After the addition was completed, the solution was aged for 3h, and then centrifuged, washed, dried, and ground to obtain aluminum-silicon double-layer coated titanium dioxide. The aluminum-silicon double-layer coated titanium dioxide was placed in a dryer and SO2 gas was introduced, where the temperature was 120°C and the gas flow rate was 5m 3 / h·kg, time 3h; The titanium dioxide with aluminum-silicon double-layer coating, the bright polyester and the stabilizer are mixed in a weight percentage of 50:50 to obtain a mixed powder, the stabilizer is added in an amount of 500-800ppm of the polyester mass, and the stabilizer is triphenyl phosphate; The mixed powder is dried at a temperature of 170°C for 15 hours, and the moisture content is controlled to be less than 30 ppm. The dried mixed powder is fed into a twin-screw for melt granulation at a twin-screw temperature of 275°C to obtain a titanium dioxide masterbatch. The intrinsic viscosity of the titanium dioxide masterbatch is 0.48 dL / g, and the intrinsic viscosity of the high-gloss polyester is 0.67 dL / g.

[0045] The FDY spinning process includes cooling, stretching and winding. The parameters of the FDY spinning process are as follows: cooling temperature 25°C, first roller speed 2200m / min, first roller temperature 85°C, second roller speed 3000m / min, second roller temperature 140°C, winding speed 2920m / min, and stretching between the first roller and the second roller.

[0046] The cross-shaped fiber has a single-filament fineness of 1.2 dtex, a breaking strength of 4.46 cN / dtex, an elongation at break of 45.0%, a network density of 19 pieces / m, a linear density deviation rate of 0.8%, a breaking strength CV value of 4.3%, a breaking elongation CV value of 9.4%, a boiling water shrinkage rate of 8%, and a wicking height greater than 153 mm.

[0047] The conventional full-dull fiber on the market has a breaking strength of less than 3.00 cN / dtex, a linear density deviation rate of 2.0-3.0%, a breaking strength CV value greater than 10.0%, a breaking elongation CV value greater than 15.0%, and a wicking height less than 150 mm.

[0048] Compared with conventional full-dull fibers on the market, the cross-shaped fibers prepared by Example 1, Example 2 and Example 3 have good mechanical properties, good moisture absorption effect, good fluidity of the polyester melt during the preparation process, and less polyester degradation during the entire preparation process.

[0049] Any numerical value cited herein includes all values ​​of lower and upper values ​​that increase by one unit from the lower limit to the upper limit, and there is at least a two-unit interval between any lower value and any higher value. For example, if the value of the quantity of a component or a process variable (such as temperature, pressure, time, etc.) is set forth to be from 1 to 90, preferably from 20 to 80, and more preferably from 30 to 70, the purpose is to illustrate that values ​​such as 15 to 85, 22 to 68, 43 to 51, 30 to 32 are also explicitly listed in the specification. For values ​​less than 1, one unit is appropriately considered to be 0.0001, 0.001, 0.01, 0.1. These are merely examples that are intended to be clearly expressed, and it can be considered that all possible combinations of numerical values ​​listed between the lowest value and the highest value are clearly set forth in the specification in a similar manner.

[0050] Unless otherwise indicated, all ranges include the endpoints and all numbers between the endpoints. "About" or "approximately" used with a range applies to both endpoints of the range. Thus, "about 20 to 30" is intended to cover "about 20 to about 30", including at least the specified endpoints.

[0051] All articles and references disclosed, including patent applications and publications, are incorporated herein by reference for all purposes. The term "consisting essentially of..." to describe a combination should include the identified elements, ingredients, parts or steps and other elements, ingredients, parts or steps that do not substantially affect the basic novel characteristics of the combination. The use of the terms "comprising" or "including" to describe a combination of elements, ingredients, parts or steps herein also contemplates embodiments that consist essentially of these elements, ingredients, parts or steps. By using the term "may", it is intended to indicate that any attribute described that "may" include is optional.

[0052] Multiple elements, ingredients, parts or steps can be provided by a single integrated element, ingredient, part or step. Alternatively, a single integrated element, ingredient, part or step can be divided into separate multiple elements, ingredients, parts or steps. The disclosure "one" or "an" used to describe an element, ingredient, part or step is not intended to exclude other elements, ingredients, parts or steps.

[0053] It should be understood that the above description is for illustration and not for limitation. Many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of the present teachings should not be determined with reference to the above description, but should be determined with reference to the appended claims and the full scope of equivalents possessed by such claims. For the purpose of comprehensiveness, all articles and references, including disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the preceding claims is not intended to be a waiver of the subject matter, nor should it be considered that the inventors did not consider the subject matter to be part of the disclosed inventive subject matter.

Claims

1. A fully matte cross-shaped fiber, characterized in that: The raw materials of the cross-shaped fiber include PET polyester and a matting agent, and the matting agent is titanium dioxide with an aluminum-silicon double-layer coating.

2. The full-dull cross-shaped fiber according to claim 1, characterized in that: The content of the matting agent is 2.0-2.2 wt %.

3. The method for preparing the fully matte cross-shaped fiber according to claim 1 or 2, characterized in that: The following steps are involved: The PET polyester and titanium dioxide masterbatch are prepared, the PET polyester and titanium dioxide masterbatch are melted to obtain a PET polyester melt, the PET polyester melt is extruded from the spinneret holes on the spinneret, and the cross-shaped fiber is obtained through an FDY spinning process; The spinneret hole is cross-shaped, and includes a transverse flow channel and a vertical flow channel perpendicular to the transverse flow channel. The length ratio of the transverse flow channel to the vertical flow channel is 1:

1. The intersection of the transverse flow channel and the vertical flow channel is the midpoint of the transverse flow channel and the vertical flow channel. The width of the transverse flow channel is the same as that of the vertical flow channel. The length and width ratio of the vertical flow channel is (3.5-5.5):

1.

4. The method for preparing the fully matte cross-shaped fiber according to claim 1, characterized in that: The intrinsic viscosity of the PET polyester melt is 0.63-0.67 dL / g.

5. The method for preparing the fully matte cross-shaped fiber according to claim 3, characterized in that: The specific steps of preparing the matting agent are: Weigh an appropriate amount of finely ground titanium dioxide, disperse it in deionized water to prepare a mass concentration of 20-25wt%, and add sodium hexametaphosphate to prepare a slurry, adjust the pH to 10-11, stir the slurry evenly, heat it to 80-85° C. and stir it, gradually drop 0.3 mol / L Na2SiO3·9H2O solution, wherein the mass of Na2SiO3 is 1.0-1.2% of titanium dioxide, and then gradually drop 1.6wt% H2SO4 to maintain the pH stable at pH=9.5, age it for 2-3h after the dropwise addition is completed, and then centrifuge, wash, dry, and grind it to obtain silicon-coated titanium dioxide; The silicon-coated titanium dioxide is dispersed in deionized water to a mass concentration of 20-25wt%, and then a 0.6mol / L NaAlO2 solution is added dropwise, and 1.6wt% H2SO4 is added simultaneously to maintain the pH value at 9.0, wherein the mass of NaAlO2 is 2.5-3.0% of the titanium dioxide. After the addition is completed, the solution is aged for 2-3h, and then centrifuged, washed, dried, and ground to obtain aluminum-silicon double-layer coated titanium dioxide; Place the aluminum-silicon double-layer coated titanium dioxide in a dryer and introduce SO2 gas at a temperature of 100-120°C and a gas flow rate of 3-5m 3 / h·kg, time 2-3h; The titanium dioxide coated with aluminum silicon double layer, the bright polyester and the stabilizer are mixed in a weight percentage of (40-50): (60-50) to obtain a mixed powder, and the amount of the stabilizer added is 500-800ppm of the polyester mass; The mixed powder is dried at a temperature of 150-170°C for 12-15 hours, and the moisture content is controlled to be less than 30ppm. The dried mixed powder is fed into a twin-screw extruder for melt granulation at a twin-screw extruder temperature of 250-275°C to obtain titanium dioxide masterbatch.

6. The method for preparing the fully matte cross-shaped fiber according to claim 5, characterized in that: The intrinsic viscosity of the titanium dioxide masterbatch is 0.45-0.48 dL / g.

7. The method for preparing the fully matte cross-shaped fiber according to claim 5, characterized in that: The intrinsic viscosity of the bright polyester is 0.64-0.67 dL / g.

8. The method for preparing the fully matte cross-shaped fiber according to claim 5, characterized in that: The stabilizer is triphenyl phosphate.

9. The method for preparing the fully matte cross-shaped fiber according to claim 3, characterized in that: The parameters of the FDY spinning process are: cooling temperature 20-25°C, first roller speed 2000-2200m / min, first roller temperature 75-85°C, second roller speed 2800-3000m / min, second roller temperature 130-140°C, and winding speed 2830-2920m / min.

10. The method for preparing the fully matte cross-shaped fiber according to claim 3, characterized in that: The cross-shaped fiber has a single-filament fineness of 0.8-1.2 dtex, a breaking strength of ≥3.30 cN / dtex, an elongation at break of 40±5.0%, a network density of 15±4 pieces / m, a linear density deviation rate of ≤1.0%, a breaking strength CV value of ≤5.0%, a breaking elongation CV value of ≤10.0%, and a boiling water shrinkage of 7.5±0.5%.