Extinction cationic polyester master batch and preparation method thereof

Abstract

The invention relates to the technical field of high polymer materials, and discloses a matting cationic polyester master batch and a preparation method thereof.The master batch is good in melt flowability and excellent in melt filtering performance and can be directly used for melt direct spinning processing; dendritic hyperbranched polyester is added into the master batch, so that the melt flowing property of cationic polyester is remarkably improved, modified titanium dioxide is also added into the master batch, the modified titanium dioxide is prepared from a titanium dioxide water-phase dispersion liquid and a cationic surface active agent, and a layer of cationic protective film is formed on the surface of titanium dioxide by a sol-gel method, so that the cationic protective film is formed on the surface of the titanium dioxide. Titanium dioxide particles are repelled under the charge action of the cationic protective film, so that the dispersity of titanium dioxide is remarkably improved, titanium dioxide agglomeration is avoided, and the filtering performance of the cationic polyester melt is remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to a matting cationic polyester masterbatch and its preparation method. Background Technology

[0002] To address the poor dyeing performance of traditional polyester fibers, a third monomer (containing a strongly acidic sodium benzenesulfonate group) was introduced into the macromolecular chain of conventional polyester PET to form a copolymer, thus preparing cationic dyeable polyester (CDP). Because this third monomer readily undergoes cationic-anionic chemical reactions with cationic dyes, macroscopically, colored dyes are easily fixed onto the fiber. Fabrics woven from this fiber readily absorb color, have a complete color spectrum, high dye uptake, and vibrant colors. They are also less prone to fading or discoloration after washing, while overcoming the shortcomings of ordinary polyester, such as pilling, poor moisture absorption, and poor antistatic properties.

[0003] Existing technology CN118166437A points out that cationic dyeable polyesters suffer from problems such as dazzling gloss and lack of drape. Therefore, it is necessary to add matting agents to solve these problems. Titanium dioxide is the most commonly used matting agent. However, direct use of titanium dioxide can lead to the coordination of sulfonic acid groups with metal ions in the cationic polyester, resulting in poor melt flowability. In addition, this invention has found that direct use of titanium dioxide also presents difficulties in dispersion. At the same time, the high concentration of cationic matrix ions affects the surface charge distribution of titanium dioxide, making it prone to agglomeration. This is also one of the reasons for the poor melt filterability of matting cationic polyester masterbatch, making it impossible to directly apply matting cationic polyester masterbatch in melt spinning processes. Summary of the Invention

[0004] To overcome the problem of poor melt filtration properties in existing matte cationic dyeable polyester masterbatches, which prevent their application in melt spinning processes, this invention provides a matte cationic dyeable polyester masterbatch and its preparation method. This masterbatch exhibits good melt flowability and excellent melt filtration performance, making it suitable for direct melt spinning. The addition of dendritic hyperbranched polyester significantly reduces the melt flowability of the cationic polyester. Furthermore, modified titanium dioxide is added to the masterbatch. This modified titanium dioxide is prepared using an aqueous titanium dioxide dispersion and a cationic surfactant. A cationic protective film is formed on the surface of the titanium dioxide using a sol-gel method. The charge effect of the cationic protective film causes repulsion among the titanium dioxide particles, significantly improving the dispersibility of titanium dioxide and preventing agglomeration, thereby significantly enhancing the melt filtration performance of the cationic polyester.

[0005] The specific technical solution of this invention is as follows: A matting cationic polyester masterbatch comprises a main material and auxiliary materials. The main material is cationic polyester and modified titanium dioxide, and the auxiliary material includes dendritic hyperbranched polyester. The modified titanium dioxide is prepared by using an aqueous dispersion of titanium dioxide and a cationic surfactant. The surface of titanium dioxide is modified by a sol-gel method to form a cationic protective film on the surface of titanium dioxide. The charge effect of the modified titanium dioxide surface film repels titanium dioxide, improving the dispersion of titanium dioxide and preventing its agglomeration, thereby improving the filtration performance of the cationic polyester.

[0006] Preferably, the mass ratio of cationic polyester to modified titanium dioxide is 7-9:1-3.

[0007] Preferably, the amount of dendritic hyperbranched polyester used is 0.5% to 5% of the main material.

[0008] Preferably, the intrinsic viscosity of the cationic polyester is 0.50 to 0.55 dL / g.

[0009] Preferably, the cationic surfactant is one or more of dodecyltrimethylammonium bromide, hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium chloride, and tetraethylammonium bromide.

[0010] Preferably, the final content of the cationic surfactant is 0.5% to 5%.

[0011] Preferably, the excipients also include a dispersant, the amount of which is 0.5-2% of the main material, and the dispersant is one or more of ethylene-vinyl acetate copolymer wax, ethylene-acrylic acid copolymer wax, maleic anhydride grafted polyethylene wax, and superdispersant.

[0012] This invention provides a matte cationic polyester masterbatch with good melt flowability and excellent melt filtration performance, which can be directly used for melt spinning.

[0013] This polyester masterbatch incorporates modified titanium dioxide and dendritic hyperbranched polyester into cationic polyester. The dendritic hyperbranched polyester has significant steric hindrance and no chain entanglement, which can weaken the interaction between polymer chain segments. Adding it to cationic polyester can significantly improve the melt index and rheological properties of cationic polyester, improve the processing fluidity of cationic polyester, and also improve the surface smoothness of the product.

[0014] Modified titanium dioxide is prepared using an aqueous dispersion of titanium dioxide and a cationic surfactant. The aqueous dispersion and cationic surfactant are combined via a sol-gel method to form a protective film on the titanium dioxide surface. This protective film isolates the titanium dioxide from direct contact with the cationic polyester, preventing coordination reactions between the titanium dioxide and sulfonic acid groups and reducing impurities. Furthermore, the negatively charged cationic protective film, when coated on the titanium dioxide surface, creates a repulsive effect between the modified titanium dioxide particles, significantly improving particle dispersibility and preventing agglomeration. This significantly enhances the melt filtration performance of the matting cationic polyester masterbatch. In addition, the high compatibility between the cationic protective film and the cationic polyester improves the uniformity of titanium dioxide within the cationic polyester masterbatch.

[0015] A method for preparing the above-mentioned matting cationic polyester masterbatch includes the following steps: (1) Add cationic surfactant to titanium dioxide aqueous dispersion, stir, centrifuge and dry to prepare modified titanium dioxide; (2) Modified titanium dioxide, dendritic hyperbranched polyester and dispersant are mixed at high speed to prepare a premix. (3) The cationic polyester is injected into the screw extrusion device to form molten cationic polyester. Then the premix is ​​fed into the fourth zone of the screw extrusion device and mixed with the molten cationic polyester. After the mixing is completed, it is extruded and pelletized to form matte cationic polyester masterbatch.

[0016] Preferably, the pH of the titanium dioxide aqueous dispersion is 7.5 to 8.5.

[0017] Preferably, the titanium dioxide content in the aqueous dispersion is 10–50 g / L, and the titanium dioxide particle size distribution is 50–400 nm.

[0018] Preferably, in step (1), the stirring time is 15-25 h, the centrifugation time is 0.1-0.5 h, the drying time is 4-10 h, and the drying temperature is 120-150 °C.

[0019] Preferably, the high-speed mixing speed in step (2) is 500-2000 r / min, and the high-speed mixing time is 5-15 min.

[0020] Preferably, the melting and mixing temperature in step (3) is 215–255°C.

[0021] Preferably, a filter screen is installed in front of the die of the screw extruder.

[0022] This invention also proposes a method for preparing the above-mentioned matting cationic polyester masterbatch. This method is simple and low-cost, and can be mass-produced. The filter screen can remove large-sized agglomerates generated during the initial processing, ensuring the stability of product quality.

[0023] Compared with the prior art, this application has the following technical effects: (1) This invention uses dendritic hyperbranched compounds as cationic polyester rheology processing aids. By utilizing their large steric hindrance and lack of chain entanglement, the interaction between molecular chain segments is weakened, thereby improving the melt index and rheological properties of the polymer. This is beneficial for the processing of cationic polyester titanium dioxide masterbatch and can also improve the smoothness of the masterbatch product surface.

[0024] (2) The modified titanium dioxide for cationic polyester prepared by the present invention forms a protective film by the interaction between the cationic surfactant and the negatively charged titanium dioxide particles, so that the particles repel each other and achieve the purpose of dispersing titanium dioxide; at the same time, the surface-modified titanium dioxide and the cationic polyester matrix material have better compatibility, which is also conducive to its uniform distribution in the matrix. Detailed Implementation

[0025] The present invention will be further described below with reference to embodiments.

[0026] Example 1: A method for preparing the above-mentioned matting cationic polyester masterbatch includes the following steps: (1) The cationic surfactant (dodecyltrimethylammonium bromide) was added to the aqueous dispersion of titanium dioxide (pH value 8.0, titanium dioxide content 20 g / L, titanium dioxide average particle size 200 nm) and stirred at room temperature for 20 h, then centrifuged for 0.2 h, and the precipitate was dried in an oven at 130 ℃ for 8 h to obtain modified titanium dioxide. The final content of the cationic surfactant was 2%. (2) The dendritic hyperbranched polyester, dispersant (ethylene-vinyl acetate copolymer wax) and modified titanium dioxide were injected into a high-speed mixer and mixed for 10 min at a mixing speed of 1500 r / min to prepare a premix. (3) The cationic polyester (chip intrinsic viscosity 0.52 dL / g) is fed into the main feed port of a twin-screw extruder (zone 1 temperature 215℃, zone 2 temperature 245℃, zone 3 temperature 255℃, zone 4 temperature 220℃, screw speed 400 r / min) for melt extrusion. The cationic polyester is melted in zones 1, 2 and 3 to form molten cationic polyester. The premix is ​​then fed into the feed port of zone 4 of the twin-screw extruder to mix the premix with the molten cationic polyester to form a mixed melt. After mixing, the mixed melt is extruded from the die of the twin-screw extruder (the die is equipped with a 30 μm pore size filter) and granulated to form matte cationic polyester masterbatch. The mass ratio of cationic polyester to modified titanium dioxide in the main material of the cationic polyester masterbatch is 7:3. The dendritic hyperbranched polyester accounts for 3% of the main material and the dispersant accounts for 1% of the main material.

[0027] Example 2: A method for preparing the above-mentioned matting cationic polyester masterbatch includes the following steps: (1) The cationic surfactant (hexadecyltrimethylammonium bromide) was added to the aqueous dispersion of titanium dioxide (pH value 8.0, titanium dioxide content 20 g / L, titanium dioxide average particle size 200 nm) and stirred at room temperature for 20 h, then centrifuged for 0.2 h, and the precipitate was dried in an oven at 130 ℃ for 8 h to obtain modified titanium dioxide. The final content of the cationic surfactant was 2%. (2) Inject dendritic hyperbranched polyester, dispersant (hyperdispersant) and modified titanium dioxide into a high-speed mixer and mix for 10 min at a mixing speed of 1500 r / min to prepare a premix. (3) The cationic polyester (chip intrinsic viscosity 0.52 dL / g) is fed into the main feed port of a twin-screw extruder (zone 1 temperature 215℃, zone 2 temperature 245℃, zone 3 temperature 255℃, zone 4 temperature 220℃, screw speed 400 r / min) for melt extrusion. The cationic polyester is melted in zones 1, 2 and 3 to form molten cationic polyester. The premix is ​​then fed into the feed port of zone 4 of the twin-screw extruder to mix the premix with the molten cationic polyester to form a mixed melt. After mixing, the mixed melt is extruded from the die of the twin-screw extruder (the die is equipped with a 30 μm pore size filter) and granulated to form matte cationic polyester masterbatch. The mass ratio of cationic polyester to modified titanium dioxide in the main material of the cationic polyester masterbatch is 7:3. The dendritic hyperbranched polyester accounts for 3% of the main material and the dispersant accounts for 1% of the main material.

[0028] Example 3: A method for preparing the above-mentioned matting cationic polyester masterbatch includes the following steps: (1) The cationic surfactant (hexadecyltrimethylammonium chloride) was added to the aqueous dispersion of titanium dioxide (pH value 8.0, titanium dioxide content 20 g / L, titanium dioxide average particle size 200 nm) and stirred at room temperature for 20 h, then centrifuged for 0.2 h, and the precipitate was dried in an oven at 130 ℃ for 8 h to obtain modified titanium dioxide. The final content of the cationic surfactant was 2%. (2) Inject dendritic hyperbranched polyester, dispersant (maleic anhydride grafted polyethylene wax) and modified titanium dioxide into a high-speed mixer and mix for 10 min at a mixing speed of 1500 r / min to prepare a premix. (3) The cationic polyester (chip intrinsic viscosity 0.52 dL / g) is fed into the main feed port of a twin-screw extruder (zone 1 temperature 215℃, zone 2 temperature 245℃, zone 3 temperature 255℃, zone 4 temperature 220℃, screw speed 400 r / min) for melt extrusion. The cationic polyester is melted in zones 1, 2 and 3 to form molten cationic polyester. The premix is ​​then fed into the feed port of zone 4 of the twin-screw extruder to mix the premix with the molten cationic polyester to form a mixed melt. After mixing, the mixed melt is extruded from the die of the twin-screw extruder (the die is equipped with a 30 μm pore size filter) and granulated to form matte cationic polyester masterbatch. The mass ratio of cationic polyester to modified titanium dioxide in the main material of the cationic polyester masterbatch is 7:3. The dendritic hyperbranched polyester accounts for 3% of the main material and the dispersant accounts for 1% of the main material.

[0029] Example 4: A method for preparing the above-mentioned matting cationic polyester masterbatch includes the following steps: (1) Add the cationic surfactant (tetraethylammonium bromide) to the aqueous dispersion of titanium dioxide (pH value 8.0, titanium dioxide content 20 g / L, titanium dioxide average particle size 200 nm) and stir at room temperature for 20 h, then centrifuge for 0.2 h, and take the precipitate and dry it in an oven at 130 ℃ for 8 h to obtain modified titanium dioxide. The final content of the cationic surfactant is 2%. (2) The dendritic hyperbranched polyester, dispersant (ethylene-acrylic acid copolymer wax) and modified titanium dioxide were injected into a high-speed mixer and mixed for 10 min at a mixing speed of 1500 r / min to prepare a premix. (3) The cationic polyester (chip intrinsic viscosity 0.52 dL / g) is fed into the main feed port of a twin-screw extruder (zone 1 temperature 215℃, zone 2 temperature 245℃, zone 3 temperature 255℃, zone 4 temperature 220℃, screw speed 400 r / min) for melt extrusion. The cationic polyester is melted in zones 1, 2 and 3 to form molten cationic polyester. The premix is ​​then fed into the feed port of zone 4 of the twin-screw extruder to mix the premix with the molten cationic polyester to form a mixed melt. After mixing, the mixed melt is extruded from the die of the twin-screw extruder (the die is equipped with a 30 μm pore size filter) and granulated to form matte cationic polyester masterbatch. The mass ratio of cationic polyester to modified titanium dioxide in the main material of the cationic polyester masterbatch is 7:3. The dendritic hyperbranched polyester accounts for 3% of the main material and the dispersant accounts for 1% of the main material.

[0030] Comparative Example 1: The difference between Comparative Example 1 and Example 1 is that the amount of dendritic hyperbranched polyester used is too high, including the following steps: (1) The cationic surfactant (dodecyltrimethylammonium bromide) was added to the aqueous dispersion of titanium dioxide (pH value 8.0, titanium dioxide content 20 g / L, titanium dioxide average particle size 180 nm) and stirred at room temperature for 18 h, then centrifuged for 0.2 h, and the precipitate was dried in an oven at 130 ℃ for 8 h to obtain modified titanium dioxide. The final content of the cationic surfactant was 2%. (2) The dendritic hyperbranched polyester, dispersant (ethylene-vinyl acetate copolymer wax) and modified titanium dioxide were injected into a high-speed mixer and mixed for 8 minutes at a mixing speed of 1400 r / min to prepare a premix. (3) The cationic polyester (chip intrinsic viscosity 0.52 dL / g) is fed into the main feed port of a twin-screw extruder (zone 1 temperature 215℃, zone 2 temperature 245℃, zone 3 temperature 255℃, zone 4 temperature 220℃, screw speed 400 r / min) for melt extrusion. The cationic polyester is melted in zones 1, 2 and 3 to form molten cationic polyester. The premix is ​​then fed into the feed port of zone 4 of the twin-screw extruder to mix the premix with the molten cationic polyester to form a mixed melt. After mixing, the mixed melt is extruded from the die of the twin-screw extruder (the die is equipped with a 30 μm pore size filter) and granulated to form matte cationic polyester masterbatch. The mass ratio of cationic polyester to modified titanium dioxide in the main material of the cationic polyester masterbatch is 7:3. The dendritic hyperbranched polyester accounts for 5% of the main material and the dispersant accounts for 1% of the main material.

[0031] Comparative Example 2: The difference between Comparative Example 2 and Example 1 is that the amount of dendritic hyperbranched polyester used is too low, including the following steps: (1) The cationic surfactant (dodecyltrimethylammonium bromide) was added to the aqueous dispersion of titanium dioxide (pH value 8.0, titanium dioxide content 20 g / L, titanium dioxide average particle size 180 nm) and stirred at room temperature for 20 h, then centrifuged for 0.2 h, and the precipitate was dried in an oven at 130 ℃ for 9 h to obtain modified titanium dioxide. The final content of the cationic surfactant was 2%. (2) The dendritic hyperbranched polyester, dispersant (ethylene-vinyl acetate copolymer wax) and modified titanium dioxide were injected into a high-speed mixer and mixed for 8 minutes at a mixing speed of 1400 r / min to prepare a premix. (3) The cationic polyester (chip intrinsic viscosity 0.52 dL / g) is fed into the main feed port of a twin-screw extruder (zone 1 temperature 215℃, zone 2 temperature 245℃, zone 3 temperature 255℃, zone 4 temperature 220℃, screw speed 400 r / min) for melt extrusion. The cationic polyester is melted in zones 1, 2 and 3 to form molten cationic polyester. The premix is ​​then fed into the feed port of zone 4 of the twin-screw extruder to mix the premix with the molten cationic polyester to form a mixed melt. After mixing, the mixed melt is extruded from the die of the twin-screw extruder (the die is equipped with a 30 μm pore size filter) and granulated to form matte cationic polyester masterbatch. The mass ratio of cationic polyester to modified titanium dioxide in the main material of the cationic polyester masterbatch is 7:3. The dendritic hyperbranched polyester accounts for 0.5% of the main material and the dispersant accounts for 1% of the main material.

[0032] Comparative Example 3: The difference between Comparative Example 3 and Example 1 is that the amount of dispersant used was too high, including the following steps: (1) The cationic surfactant (dodecyltrimethylammonium bromide) was added to the aqueous dispersion of titanium dioxide (pH value 8.0, titanium dioxide content 20 g / L, titanium dioxide average particle size 180 nm) and stirred at room temperature for 20 h, then centrifuged for 0.2 h, and the precipitate was dried in an oven at 130 ℃ for 9 h to obtain modified titanium dioxide. The final content of the cationic surfactant was 2%. (2) The dendritic hyperbranched polyester, dispersant (ethylene-vinyl acetate copolymer wax) and modified titanium dioxide were injected into a high-speed mixer and mixed for 10 min at a mixing speed of 1500 r / min to prepare a premix. (3) The cationic polyester (chip intrinsic viscosity 0.52 dL / g) is fed into the main feed port of a twin-screw extruder (zone 1 temperature 215℃, zone 2 temperature 245℃, zone 3 temperature 255℃, zone 4 temperature 220℃, screw speed 400 r / min) for melt extrusion. The cationic polyester is melted in zones 1, 2 and 3 to form molten cationic polyester. The premix is ​​then fed into the feed port of zone 4 of the twin-screw extruder to mix the premix with the molten cationic polyester to form a mixed melt. After mixing, the mixed melt is extruded from the die of the twin-screw extruder (the die is equipped with a 30 μm pore size filter) and granulated to form matte cationic polyester masterbatch. The mass ratio of cationic polyester to modified titanium dioxide in the main material of the cationic polyester masterbatch is 7:3. The dendritic hyperbranched polyester accounts for 3% of the main material and the dispersant accounts for 2% of the main material.

[0033] Comparative Example 4: The difference between Comparative Example 4 and Example 1 is that the amount of dispersant used was too low, including the following steps: (1) The cationic surfactant (dodecyltrimethylammonium bromide) was added to the aqueous dispersion of titanium dioxide (pH value 7.8, titanium dioxide content 20 g / L, titanium dioxide average particle size 180 nm) and stirred at room temperature for 16 h, then centrifuged for 0.2 h, and the precipitate was dried in an oven at 120 ℃ for 10 h to obtain modified titanium dioxide. The final content of the cationic surfactant was 2%. (2) The dendritic hyperbranched polyester, dispersant (ethylene-vinyl acetate copolymer wax) and modified titanium dioxide were injected into a high-speed mixer and mixed for 12 minutes at a mixing speed of 1300 r / min to prepare a premix. (3) The cationic polyester (chip intrinsic viscosity 0.52 dL / g) is fed into the main feed port of a twin-screw extruder (zone 1 temperature 215℃, zone 2 temperature 245℃, zone 3 temperature 255℃, zone 4 temperature 225℃, screw speed 380 r / min) for melt extrusion. The cationic polyester is melted in zones 1, 2 and 3 to form molten cationic polyester. The premix is ​​then fed into the fourth feed port of the twin-screw extruder to mix the premix with the molten cationic polyester to form a mixed melt. After mixing, the mixed melt is extruded from the die of the twin-screw extruder (the die is equipped with a 30 μm pore size filter) and granulated to form matte cationic polyester masterbatch. The mass ratio of cationic polyester to modified titanium dioxide in the main material of the cationic polyester masterbatch is 7:3. The dendritic hyperbranched polyester accounts for 3% of the main material and the dispersant accounts for 0.5% of the main material.

[0034] Comparative Example 5: The difference between Comparative Example 5 and Example 1 is that the twin-screw rotation speed is too high, including the following steps: (1) The cationic surfactant (dodecyltrimethylammonium bromide) was added to the aqueous dispersion of titanium dioxide (pH value 8.0, titanium dioxide content 20 g / L, titanium dioxide average particle size 200 nm) and stirred at room temperature for 20 h, then centrifuged for 0.2 h, and the precipitate was dried in an oven at 130 ℃ for 8 h to obtain modified titanium dioxide. The final content of the cationic surfactant was 2%. (2) The dendritic hyperbranched polyester, dispersant (ethylene-vinyl acetate copolymer wax) and modified titanium dioxide were injected into a high-speed mixer and mixed for 10 min at a mixing speed of 1500 r / min to prepare a premix. (3) The cationic polyester (chip intrinsic viscosity 0.51dL / g) is fed into the main feed port of a twin-screw extruder (zone 1 temperature 215℃, zone 2 temperature 245℃, zone 3 temperature 255℃, zone 4 temperature 220℃, screw speed 500r / min) for melt extrusion. The cationic polyester is melted in zones 1, 2 and 3 to form molten cationic polyester. The premix is ​​then fed into the feed port of zone 4 of the twin-screw extruder to mix the premix with the molten cationic polyester to form a mixed melt. After mixing, the mixed melt is extruded from the die of the twin-screw extruder (the die is equipped with a 30μm pore size filter) and granulated to form matte cationic polyester masterbatch. The mass ratio of cationic polyester to modified titanium dioxide in the main material of the cationic polyester masterbatch is 7:3. The dendritic hyperbranched polyester accounts for 3% of the main material and the dispersant accounts for 1% of the main material.

[0035] Comparative Example 6: The difference between Comparative Example 6 and Example 1 is that the twin-screw rotation speed is too low, including the following steps: (1) The cationic surfactant (dodecyltrimethylammonium bromide) was added to the aqueous dispersion of titanium dioxide (pH value 7.6, titanium dioxide content 15 g / L, titanium dioxide average particle size 100 nm) and stirred at room temperature for 20 h, then centrifuged for 0.2 h, and the precipitate was dried in an oven at 130 ℃ for 8 h to obtain modified titanium dioxide. The final content of the cationic surfactant was 2%. (2) The dendritic hyperbranched polyester, dispersant (ethylene-vinyl acetate copolymer wax) and modified titanium dioxide were injected into a high-speed mixer and mixed for 10 min at a mixing speed of 1500 r / min to prepare a premix. (3) The cationic polyester (chip intrinsic viscosity 0.51dL / g) is fed into the main feed port of a twin-screw extruder (zone 1 temperature 215℃, zone 2 temperature 245℃, zone 3 temperature 255℃, zone 4 temperature 220℃, screw speed 200r / min) for melt extrusion. The cationic polyester is melted in zones 1, 2 and 3 to form molten cationic polyester. The premix is ​​then fed into the feed port of zone 4 of the twin-screw extruder to mix the premix with the molten cationic polyester to form a mixed melt. After mixing, the mixed melt is extruded from the die of the twin-screw extruder (the die is equipped with a 30μm pore size filter) and granulated to form matte cationic polyester masterbatch. The mass ratio of cationic polyester to modified titanium dioxide in the main material of the cationic polyester masterbatch is 7:3. The dendritic hyperbranched polyester accounts for 3% of the main material and the dispersant accounts for 1% of the main material.

[0036] Comparative Example 7: The difference between Comparative Example 7 and Example 1 is that the temperature in Zone 4 is too high, including the following steps: (1) The cationic surfactant (dodecyltrimethylammonium bromide) was added to the aqueous dispersion of titanium dioxide (pH value 8.0, titanium dioxide content 20 g / L, titanium dioxide average particle size 200 nm) and stirred at room temperature for 20 h, then centrifuged for 0.2 h, and the precipitate was dried in an oven at 130 ℃ for 8 h to obtain modified titanium dioxide. The final content of the cationic surfactant was 2%. (2) The dendritic hyperbranched polyester, dispersant (ethylene-vinyl acetate copolymer wax) and modified titanium dioxide were injected into a high-speed mixer and mixed for 10 min at a mixing speed of 1500 r / min to prepare a premix. (3) The cationic polyester (chip intrinsic viscosity 0.51dL / g) is fed into the main feed port of a twin-screw extruder (zone 1 temperature 215℃, zone 2 temperature 245℃, zone 3 temperature 255℃, zone 4 temperature 230℃, screw speed 400r / min) for melt extrusion. The cationic polyester is melted in zones 1, 2 and 3 to form molten cationic polyester. The premix is ​​then fed into the feed port of zone 4 of the twin-screw extruder to mix the premix with the molten cationic polyester to form a mixed melt. After mixing, the mixed melt is extruded from the die of the twin-screw extruder (the die is equipped with a 30μm pore size filter) and granulated to form matte cationic polyester masterbatch. The mass ratio of cationic polyester to modified titanium dioxide in the main material of the cationic polyester masterbatch is 7:3. The dendritic hyperbranched polyester accounts for 3% of the main material and the dispersant accounts for 1% of the main material.

[0037] Comparative Example 8: The difference between Comparative Example 8 and Example 1 is that the temperature in Zone 4 is too low, including the following steps: (1) The cationic surfactant (dodecyltrimethylammonium bromide) was added to the aqueous dispersion of titanium dioxide (pH value 8.0, titanium dioxide content 20 g / L, titanium dioxide average particle size 200 nm) and stirred at room temperature for 20 h, then centrifuged for 0.2 h, and the precipitate was dried in an oven at 130 ℃ for 8 h to obtain modified titanium dioxide. The final content of the cationic surfactant was 2%. (2) The dendritic hyperbranched polyester, dispersant (ethylene-vinyl acetate copolymer wax) and modified titanium dioxide were injected into a high-speed mixer and mixed for 10 min at a mixing speed of 1500 r / min to prepare a premix. (3) The cationic polyester (chip intrinsic viscosity 0.51dL / g) is fed into the main feed port of a twin-screw extruder (zone 1 temperature 215℃, zone 2 temperature 245℃, zone 3 temperature 255℃, zone 4 temperature 210℃, screw speed 400r / min) for melt extrusion. The cationic polyester is melted in zones 1, 2 and 3 to form molten cationic polyester. The premix is ​​then fed into the feed port of zone 4 of the twin-screw extruder to mix the premix with the molten cationic polyester to form a mixed melt. After mixing, the mixed melt is extruded from the die of the twin-screw extruder (the die is equipped with a 30μm pore size filter) and granulated to form matte cationic polyester masterbatch. The mass ratio of cationic polyester to modified titanium dioxide in the main material of the cationic polyester masterbatch is 7:3. The dendritic hyperbranched polyester accounts for 3% of the main material and the dispersant accounts for 1% of the main material.

[0038] Comparative Example 9: The difference between Comparative Example 9 and Example 1 is that the filter mesh size is too large, including the following steps: (1) The cationic surfactant (dodecyltrimethylammonium bromide) was added to the aqueous dispersion of titanium dioxide (pH value 8.0, titanium dioxide content 20 g / L, titanium dioxide average particle size 200 nm) and stirred at room temperature for 20 h, then centrifuged for 0.2 h, and the precipitate was dried in an oven at 130 ℃ for 8 h to obtain modified titanium dioxide. The final content of the cationic surfactant was 2%. (2) The dendritic hyperbranched polyester, dispersant (ethylene-vinyl acetate copolymer wax) and modified titanium dioxide were injected into a high-speed mixer and mixed for 10 min at a mixing speed of 1500 r / min to prepare a premix. (3) The cationic polyester (chip intrinsic viscosity 0.51dL / g) is fed into the main feed port of a twin-screw extruder (zone 1 temperature 215℃, zone 2 temperature 245℃, zone 3 temperature 255℃, zone 4 temperature 220℃, screw speed 200r / min) for melt extrusion. The cationic polyester is melted in zones 1, 2 and 3 to form molten cationic polyester. The premix is ​​then fed into the feed port of zone 4 of the twin-screw extruder to mix the premix with the molten cationic polyester to form a mixed melt. After mixing, the mixed melt is extruded from the die of the twin-screw extruder (the die is equipped with a 50μm pore size filter) and granulated to form matte cationic polyester masterbatch. The mass ratio of cationic polyester to modified titanium dioxide in the main material of the cationic polyester masterbatch is 7:3. The dendritic hyperbranched polyester accounts for 3% of the main material and the dispersant accounts for 1% of the main material.

[0039] Comparative Example 10: The difference between Comparative Example 10 and Example 1 is that the filter mesh size is too small, which includes the following steps: (1) The cationic surfactant (dodecyltrimethylammonium bromide) was added to the aqueous dispersion of titanium dioxide (pH value 8.0, titanium dioxide content 20 g / L, titanium dioxide average particle size 200 nm) and stirred at room temperature for 20 h, then centrifuged for 0.2 h, and the precipitate was dried in an oven at 130 ℃ for 8 h to obtain modified titanium dioxide. The final content of the cationic surfactant was 2%. (2) The dendritic hyperbranched polyester, dispersant (ethylene-vinyl acetate copolymer wax) and modified titanium dioxide were injected into a high-speed mixer and mixed for 10 min at a mixing speed of 1500 r / min to prepare a premix. (3) The cationic polyester (chip intrinsic viscosity 0.51dL / g) is fed into the main feed port of a twin-screw extruder (zone 1 temperature 215℃, zone 2 temperature 245℃, zone 3 temperature 255℃, zone 4 temperature 220℃, screw speed 200r / min) for melt extrusion. The cationic polyester is melted in zones 1, 2 and 3 to form molten cationic polyester. The premix is ​​then fed into the feed port of zone 4 of the twin-screw extruder to mix the premix with the molten cationic polyester to form a mixed melt. After mixing, the mixed melt is extruded from the die of the twin-screw extruder (the die is equipped with a 20μm pore size filter) and granulated to form matte cationic polyester masterbatch. The mass ratio of cationic polyester to modified titanium dioxide in the main material of the cationic polyester masterbatch is 7:3. The dendritic hyperbranched polyester accounts for 3% of the main material and the dispersant accounts for 1% of the main material.

[0040] Comparative Example 11: The difference between Comparative Example 11 and Example 1 is that the amount of cationic surfactant used was too high, including the following steps: (1) The cationic surfactant (dodecyltrimethylammonium bromide) was added to the aqueous dispersion of titanium dioxide (pH value 8.0, titanium dioxide content 20 g / L, titanium dioxide average particle size 200 nm) and stirred at room temperature for 20 h, then centrifuged for 0.2 h, and the precipitate was dried in an oven at 130 ℃ for 8 h to obtain modified titanium dioxide. The final content of the cationic surfactant was 3%. (2) The dendritic hyperbranched polyester, dispersant (ethylene-vinyl acetate copolymer wax) and modified titanium dioxide were injected into a high-speed mixer and mixed for 10 min at a mixing speed of 1500 r / min to prepare a premix. (3) The cationic polyester (chip intrinsic viscosity 0.51dL / g) is fed into the main feed port of a twin-screw extruder (zone 1 temperature 215℃, zone 2 temperature 245℃, zone 3 temperature 255℃, zone 4 temperature 220℃, screw speed 200r / min) for melt extrusion. The cationic polyester is melted in zones 1, 2 and 3 to form molten cationic polyester. The premix is ​​then fed into the feed port of zone 4 of the twin-screw extruder to mix the premix with the molten cationic polyester to form a mixed melt. After mixing, the mixed melt is extruded from the die of the twin-screw extruder (the die is equipped with a 30μm pore size filter) and granulated to form matte cationic polyester masterbatch. The mass ratio of cationic polyester to modified titanium dioxide in the main material of the cationic polyester masterbatch is 7:3. The dendritic hyperbranched polyester accounts for 3% of the main material and the dispersant accounts for 1% of the main material.

[0041] Comparative Example 12: The difference between Comparative Example 12 and Example 1 is that the amount of cationic surfactant used was too low, including the following steps: (1) The cationic surfactant (dodecyltrimethylammonium bromide) was added to the aqueous dispersion of titanium dioxide (pH value 8.0, titanium dioxide content 20 g / L, titanium dioxide average particle size 200 nm) and stirred at room temperature for 20 h, then centrifuged for 0.2 h, and the precipitate was dried in an oven at 130 ℃ for 8 h to obtain modified titanium dioxide. The final content of the cationic surfactant was 1%. (2) The dendritic hyperbranched polyester, dispersant (ethylene-vinyl acetate copolymer wax) and modified titanium dioxide were injected into a high-speed mixer and mixed for 10 min at a mixing speed of 1500 r / min to prepare a premix. (3) The cationic polyester (chip intrinsic viscosity 0.51dL / g) is fed into the main feed port of a twin-screw extruder (zone 1 temperature 215℃, zone 2 temperature 245℃, zone 3 temperature 255℃, zone 4 temperature 220℃, screw speed 200r / min) for melt extrusion. The cationic polyester is melted in zones 1, 2 and 3 to form molten cationic polyester. The premix is ​​then fed into the feed port of zone 4 of the twin-screw extruder to mix the premix with the molten cationic polyester to form a mixed melt. After mixing, the mixed melt is extruded from the die of the twin-screw extruder (the die is equipped with a 30μm pore size filter) and granulated to form matte cationic polyester masterbatch. The mass ratio of cationic polyester to modified titanium dioxide in the main material of the cationic polyester masterbatch is 7:3. The dendritic hyperbranched polyester accounts for 3% of the main material and the dispersant accounts for 1% of the main material.

[0042] Comparative Example 13: The difference between Comparative Example 13 and Example 1 is that no dendritic hyperbranched polyester was added, and the following steps were included: (1) The cationic surfactant (dodecyltrimethylammonium bromide) was added to the aqueous dispersion of titanium dioxide (pH value 8.0, titanium dioxide content 20 g / L, titanium dioxide average particle size 200 nm) and stirred at room temperature for 20 h, then centrifuged for 0.2 h, and the precipitate was dried in an oven at 130 ℃ for 8 h to obtain modified titanium dioxide. The final content of the cationic surfactant was 2%. (2) The dispersant (ethylene-vinyl acetate copolymer wax) and modified titanium dioxide were injected into a high-speed mixer and mixed for 10 min at a mixing speed of 1500 r / min to prepare a premix. (3) The cationic polyester (chip intrinsic viscosity 0.52 dL / g) is fed into the main feed port of a twin-screw extruder (zone 1 temperature 215℃, zone 2 temperature 245℃, zone 3 temperature 255℃, zone 4 temperature 220℃, screw speed 400 r / min) for melt extrusion. The cationic polyester is melted in zones 1, 2 and 3 to form molten cationic polyester. The premix is ​​then fed into the feed port of zone 4 of the twin-screw extruder to mix the premix with the molten cationic polyester to form a mixed melt. After mixing, the mixed melt is extruded from the die of the twin-screw extruder (the die is equipped with a 30 μm pore size filter) and granulated to form matte cationic polyester masterbatch. The mass ratio of cationic polyester to modified titanium dioxide in the main material of the cationic polyester masterbatch is 7:3, and the dispersant in the auxiliary material accounts for 1% of the main material.

[0043] Comparative Example 14: The difference between Comparative Example 14 and Example 1 is that the cationic polyester and premix are all fed in from the main feed port, including the following steps: (1) The cationic surfactant (dodecyltrimethylammonium bromide) was added to the aqueous dispersion of titanium dioxide (pH value 8.0, titanium dioxide content 20 g / L, titanium dioxide average particle size 200 nm) and stirred at room temperature for 20 h, then centrifuged for 0.2 h, and the precipitate was dried in an oven at 130 ℃ for 8 h to obtain modified titanium dioxide. The final content of the cationic surfactant was 2%. (2) The dendritic hyperbranched polyester, dispersant (ethylene-vinyl acetate copolymer wax) and modified titanium dioxide were injected into a high-speed mixer and mixed for 10 min at a mixing speed of 1500 r / min to prepare a premix. (3) The cationic polyester (chip intrinsic viscosity 0.52 dL / g) and premix were fed into the main feed port of a twin-screw extruder (zone 1 temperature 215℃, zone 2 temperature 245℃, zone 3 temperature 255℃, zone 4 temperature 220℃, screw speed 400 r / min) for melt mixing. After mixing, the melt was extruded from the die of the twin-screw extruder (the die is equipped with a 30 μm pore size filter) and granulated to produce matte cationic polyester masterbatch. The mass ratio of cationic polyester to modified titanium dioxide in the main material of the cationic polyester masterbatch was 7:3. The dendritic hyperbranched polyester accounted for 3% of the main material and the dispersant accounted for 1% of the main material.

[0044] Comparative Example 15: The difference between Comparative Example 15 and Example 1 is that no filter screen is provided at the mold head, and the following steps are included: (1) The cationic surfactant (dodecyltrimethylammonium bromide) was added to the aqueous dispersion of titanium dioxide (pH value 8.0, titanium dioxide content 20 g / L, titanium dioxide average particle size 200 nm) and stirred at room temperature for 20 h, then centrifuged for 0.2 h, and the precipitate was dried in an oven at 130 ℃ for 8 h to obtain modified titanium dioxide. The final content of the cationic surfactant was 2%. (2) The dendritic hyperbranched polyester, dispersant (ethylene-vinyl acetate copolymer wax) and modified titanium dioxide were injected into a high-speed mixer and mixed for 10 min at a mixing speed of 1500 r / min to prepare a premix. (3) Cationic polyester (chip intrinsic viscosity 0.52 dL / g) is fed into the main feed port of a twin-screw extruder (zone 1 temperature 215℃, zone 2 temperature 245℃, zone 3 temperature 255℃, zone 4 temperature 220℃, screw speed 400 r / min) for melt extrusion. The cationic polyester is melted in zones 1, 2 and 3 to form molten cationic polyester. Then, the premix is ​​fed into the feed port of zone 4 of the twin-screw extruder to mix the premix with the molten cationic polyester to form a mixed melt. After mixing, the mixed melt is extruded from the die of the twin-screw extruder and granulated to form matte cationic polyester masterbatch. The mass ratio of cationic polyester to modified titanium dioxide in the main material of the cationic polyester masterbatch is 7:3. The dendritic hyperbranched polyester accounts for 3% of the main material and the dispersant accounts for 1% of the main material.

[0045] Comparative Example 16: The difference between Comparative Example 16 and Example 1 is that unmodified titanium dioxide was used, and the following steps were included: (1) Dendritic hyperbranched polyester, dispersant (ethylene-vinyl acetate copolymer wax), and titanium dioxide (average particle size of titanium dioxide is 200 nm) were injected into a high-speed mixer and mixed for 10 min at a mixing speed of 1500 r / min to prepare a premix; (2) Cationic polyester (chip intrinsic viscosity 0.52 dL / g) was fed into the main feed port of a twin-screw extruder (zone 1 temperature 215℃, zone 2 temperature 245℃, zone 3 temperature 255℃, zone 4 temperature 220℃, screw speed 400 r / min) for melt extrusion. The cationic polyester is melted in zones one, two, and three to form molten cationic polyester. The premix is ​​then fed into the feed port of zone four of a twin-screw extruder to mix the premix with the molten cationic polyester to form a mixed melt. After mixing, the mixed melt is extruded from the die of the twin-screw extruder (the die is equipped with a 30μm pore size filter) and granulated to produce matte cationic polyester masterbatch. The mass ratio of cationic polyester to modified titanium dioxide in the main material of the cationic polyester masterbatch is 7:3. The dendritic hyperbranched polyester accounts for 3% of the main material and the dispersant accounts for 1% of the main material.

[0046] Example of detection: The material properties of the matte cationic polyester masterbatches prepared in Examples 1 to 4 and Comparative Examples 1 to 16 were tested. The test methods were carried out in accordance with the contents disclosed in the industry standard "FZ / T 51019-2021 Polyester Fiber Masterbatch". The test results are shown in Table 1. Table 1 Material characteristics of matte cationic polyester masterbatch As shown in Table 1, the intrinsic viscosity of the matte cationic polyester masterbatches prepared in Examples 1 to 4 is 0.32–0.34 dL / g, the melting point is 227.9–229.1 °C, the melt flow rate is 43–47 g / 10 min, the pressure filtration value is 0.23–0.26 bar / g, the residue on a 100-mesh sieve is 1, and the residue on a 200-mesh sieve is 17–21.

[0047] Examples 1, 2, and 13 compared the amounts of dendritic hyperbranched polyester. The results showed that the melt flow rate of the matte cationic polyester masterbatch was significantly increased after the addition of dendritic hyperbranched polyester, and the higher the amount of dendritic hyperbranched polyester added, the higher the melt flow rate of the matte cationic polyester masterbatch. In addition, the results of 2 and 13 showed that the melt pressure filtration value of the masterbatch corresponding to the formulation with lower melt flow value was also reduced, indicating that titanium dioxide could not be well dispersed in the matrix, and the pressure filtration value and sieve residue value increased significantly, which was not conducive to its subsequent spinning use.

[0048] Examples 1, 3, and 4 compared the amount of dispersant used. The results showed that adding dispersant could significantly improve the dispersion performance of titanium dioxide in the masterbatch. The higher the amount added, the smaller the pressure filtration value and the smaller the sieve residue, the higher the filtration performance of the matting cationic polyester masterbatch.

[0049] Examples 1, 5, 6, 7, and 8 compared the screw speed and the temperature of the fourth mixing zone. The results showed that increasing the twin-screw speed or raising the mixing zone temperature could enhance the shearing action between the melt and titanium dioxide, improve the dispersion performance of the masterbatch, but the intrinsic viscosity of the masterbatch also decreased. When the twin-screw speed or the mixing zone temperature was reduced, the pressure filter value and the residue on the sieve increased accordingly.

[0050] Examples 1, 9, 10, and 15 compared the filter screens. The results showed that when a filter screen was not installed at the die head in the masterbatch preparation process, the filter pressure value and sieve residue of the masterbatch were significantly improved. The smaller the pore size of the installed filter screen, the better the filtration effect on impurities in the melt, and the lower the filter pressure value and sieve residue of the prepared masterbatch.

[0051] Examples 1, 11, 12 and 16 compared titanium dioxide. The results showed that modifying titanium dioxide with a cationic surfactant can significantly improve the dispersion performance of titanium dioxide in a cationic polyester matrix. Unmodified titanium dioxide agglomerates severely in cationic polyester and is difficult to disperse.

[0052] Comparative Examples 1 and 13 compared the feeding steps. The results showed that when all materials were added from the main feed, the masterbatch dispersion performance was slightly worse than that of the side-feeding process. This is because the cationic polyester matrix is ​​in the form of slices, while other materials are in the form of powder. The uneven premixing and dispersion increased the difficulty of mixing and dispersing during the processing.

[0053] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, alterations, and equivalent transformations made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A matte cationic polyester masterbatch, characterized in that, The raw materials include main materials and auxiliary materials. The main materials are cationic polyester and modified titanium dioxide, and the auxiliary materials include dendritic hyperbranched polyester. The modified titanium dioxide is made from titanium dioxide aqueous dispersion and cationic surfactant.

2. The matte cationic polyester masterbatch according to claim 1, characterized in that, The mass ratio of cationic polyester to modified titanium dioxide is 7~9:1~3; the amount of dendritic hyperbranched polyester used is 0.5~5% of the main material.

3. The matte cationic polyester masterbatch according to claim 1 or 2, characterized in that, The intrinsic viscosity of the cationic polyester is 0.50~0.55 dL / g.

4. The matte cationic polyester masterbatch according to claim 1, characterized in that, The cationic surfactant is one or more selected from dodecyltrimethylammonium bromide, hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium chloride, and tetraethylammonium bromide, and the final content of the cationic surfactant is 0.5% to 5%.

5. The matte cationic polyester masterbatch according to claim 1, characterized in that, The excipients also include a dispersant, the amount of which is 0.5-2% of the main material. The dispersant is one or more of ethylene-vinyl acetate copolymer wax, ethylene-acrylic acid copolymer wax, maleic anhydride grafted polyethylene wax, and superdispersant.

6. A method for preparing a matte cationic polyester masterbatch according to any one of claims 1 to 5, characterized in that, Includes the following steps: (1) Add cationic surfactant to titanium dioxide aqueous dispersion, stir, centrifuge and dry to prepare modified titanium dioxide; (2) Modified titanium dioxide, dendritic hyperbranched polyester and dispersant are mixed at high speed to prepare a premix. (3) The cationic polyester is injected into the screw extrusion device to form molten cationic polyester. Then the premix is ​​fed into the fourth zone of the screw extrusion device and mixed with the molten cationic polyester. After the mixing is completed, it is extruded and pelletized to form matte cationic polyester masterbatch.

7. The matte cationic polyester masterbatch according to claim 6, characterized in that, The pH of the aqueous dispersion of titanium dioxide is 7.5 to 8.5; the content of titanium dioxide in the aqueous dispersion of titanium dioxide is 10 to 50 g / L, and the particle size distribution of titanium dioxide is 50 to 400 nm.

8. The preparation method according to claim 6, characterized in that, In step (1), the stirring time is 15~25 h, the centrifugation time is 0.1~0.5 h, the drying time is 4~10 h, and the drying temperature is 120~150 ℃.

9. The preparation method according to claim 6, characterized in that, In step (2), the high-speed mixing speed is 500~2000 r / min, and the high-speed mixing time is 5~15 min.

10. The preparation method according to claim 6, characterized in that, The melting and mixing temperature in step (3) is 215~255℃.

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