Preparation method of high-content titanium dioxide fiber and hidden perspiration knitted fabric

Abstract

The invention relates to a preparation method of a high-content titanium dioxide fiber and hidden sweat stain knitted fabric. The preparation method comprises the following steps: firstly, carrying out primary hydrophobization treatment on TiO2 particles through silane coupling KH-550; a block copolymer PEO-PPO-PEO dispersing agent is introduced, so that agglomeration of the powder is inhibited; directly introducing the TiO2 subjected to surface modification treatment into a polyester polymerization system to prepare polyester with ultrahigh TiO2 content; pOY (polyester pre-oriented yarn) is spun by polyester, and 50D / 36F DTY and 75D / 36F DTY with ultrahigh TiO2 content are prepared by elasticizing; two types of tuck stitch fabrics and one type of single jersey stitch fabrics are developed. The super-high TiO2 + tuck stitch is adopted, the high refractive index (2.4-2.9) of nano TiO2 can scatter visible light, reduce the optical contrast ratio of sweat stains and a fiber matrix and ensure smooth air circulation of the fabric, so that the fabric has excellent moisture absorption and quick drying performance, moisture can be quickly evaporated, the air permeability and wicking effect of the fabric are improved, and the fabric has good moisture absorption and quick drying effects. Water vapor on the inner side of the fabric can be rapidly conducted to the outer side of the fabric, and a good sweat stain hiding effect is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of fabric textiles, and in particular to a method for preparing high-content titanium dioxide fiber and sweat-resistant knitted fabrics. Background Art

[0002] With the improvement of living standards and growing health awareness, the market demand for functional textiles is growing. As functional fabrics that effectively conceal sweat stains and maintain a neat appearance, sweat-resistant fabrics have broad application prospects in sportswear, professional attire, and everyday wear. Traditional polyester fibers (including fully matte fibers) have limitations in moisture wicking properties, and sweat stains easily leave visible marks on clothing, affecting both aesthetics and comfort.

[0003] Titanium dioxide (TiO2) is a high-performance material widely used in textiles, photocatalysis, coatings, energy storage, and other fields. Anatase titanium dioxide offers advantages such as high whiteness, a high refractive index (a significant difference in refractive index with polyester), non-toxicity, low production costs, and a wide range of raw material sources. It is widely used in the manufacture of standard semi-matt and matte fibers. Currently, the barrier and UV resistance of standard matte fabrics only meet general textile requirements, while high-end, sweat-resistant fabrics (TiO2 addition levels of ~10wt%) are rarely used.

[0004] Ultra-high titanium dioxide content fibers not only offer excellent UV protection but also significantly improve the fiber's optical properties, rendering them "invisible" to perspiration. This is primarily due to the high refractive index (2.4-2.9) of nano-TiO2, which scatters visible light and reduces the optical contrast between perspiration and the fiber matrix. However, at high loadings (5-15wt%), nanoparticle aggregation can lead to a decrease in fiber performance. Traditional methods (such as mechanical mixing and simple surface modification) have difficulty achieving single-particle dispersion. Summary of the Invention

[0005] In order to overcome the technical problems described in the background art, the present invention provides a method for preparing high-content titanium dioxide fiber and sweat-hidden knitted fabric.

[0006] A method for preparing high-content titanium dioxide fiber and sweat-resistant knitted fabric comprises the following steps:

[0007] Step S1: firstly perform primary hydrophobic treatment on TiO2 particles by using silane couple KH-550;

[0008] Step S2: introducing a block copolymer PEO-PPO-PEO dispersant to form a steric hindrance and electrostatic repulsion synergistic effect to inhibit powder agglomeration;

[0009] Step S3: Using in-situ polymerization technology, the TiO2 that has undergone the above-mentioned surface modification treatment is directly introduced into the polyester polymerization system. PTA, EG, and TiO2 are added to the 3L polycondensation reaction and then directly esterified at a temperature of 230-260°C and a pressure of 0.3-0.5 MPa to prepare PET resin. The TiO2 is evenly distributed between the polyester molecular chains through an in-situ dispersion technology to prepare a polyester with ultra-high TiO2 content.

[0010] Step S4: The ultra-high TiO2 content polyester prepared in step S3 is spun into POY by polyester spinning, and then subjected to stretching to produce ultra-high TiO2 content 50D / 36F DTY and 75D / 36F DTY;

[0011] Step S5: Develop two tuck weave fabrics and one jersey weave fabric.

[0012] Preferably, the silane couple KH-550 in step S1 of the present invention is 3-aminopropyltriethoxysilane;

[0013] Preferably, the reaction process of step S1 of the present invention is:

[0014] The reaction temperature is 60-70°C, the reaction time is 2-4 hours, and the mass ratio of 3-aminopropyltriethoxysilane to TiO2 is 1:10-1:15, which accelerates the hydrolysis and condensation reaction of silane;

[0015] The charge regulation of step S1 is as follows: under acidic conditions of pH = 4-6, the surface potential of TiO2 modified with 3-aminopropyltriethoxysilane is adjusted from -30 mV to +15 mV, providing electrostatic drive for subsequent dispersant adsorption.

[0016] Preferably, the PEO-PPO-PEO dispersant in step S2 of the present invention is composed of polyethylene oxide and polypropylene oxide blocks;

[0017] Preferably, the reaction process of step S2 of the present invention is:

[0018] Add PEO-PPO-PEO dispersant dropwise to the premixed system, control the pH of the system to 7.5-8.5 to promote the ionization of PEO segments, and the shear rate to 8000-12000 rpm;

[0019] Anchoring adsorption: The hydrophobic PPO chain segment of the copolymer is bound to the hydrophobic layer of 3-aminopropyltriethoxysilane through van der Waals force, and the hydrophilic PEO chain segment extends outward to form a "polymer brush" with a thickness of 5-10nm.

[0020] Preferably, in step S3 of the present invention, the amount of PTA is 3 mol, the amount of EG is 5.4 mol, and the amount of TiO2 is 0.07 mol.

[0021] Preferably, the present invention adopts a 30" 28G double-sided machine-woven tuck mesh structure to develop a tuck structure fabric; the yarn arrangement method is: ①③⑤⑦ are all ultra-high TiO2 content 75D / 36F DTY, the line length is 15.6 cm / 50N, and the yarn feeding ratio is 45%; ②④⑥⑧ are all ultra-high TiO2 content 50D / 36F DTY, the line length is 13 cm / 50N, the yarn feeding ratio is 56.19%, the needle arrangement method is: 1212, the front side is a full-needle sweat fabric, and the back side forms a tuck breathable and moisture-conducting groove structure.

[0022] Preferably, the present invention adopts 34" 28G double-sided machine to weave the tuck mesh structure and develop the tuck weave fabric; the yarn arrangement method is: ①③⑤⑦⑨ All are ultra-high TiO2 content 75D / 36F DTY, wire length is 12.3cm / 50N, yarn eating ratio is 45.62%, ②④⑥⑧⑩ They are all 50D / 36F DTY with ultra-high TiO2 content, with a line length of 12.3cm / 50N, a yarn feeding ratio of 54.38%, and a needle arrangement method of 12 1213. The front side is a full-needle jersey fabric, and the back side forms a loop-shaped breathable and moisture-conducting groove structure.

[0023] Preferably, the present invention adopts a 30" 28G large circular knitting machine and ultra-high TiO2 content 75D / 36F DTY to develop single jersey fabrics.

[0024] The technical solution of the present invention has the following advantages compared with the prior art:

[0025] 1. A two-stage surface modification is adopted to realize the multi-level surface functionalization of TiO2 powder. The TiO2 particles are first subjected to primary hydrophobic treatment by a silane coupling agent, and then a block copolymer dispersant is introduced to form a synergistic effect of steric hindrance and electrostatic repulsion to inhibit agglomeration.

[0026] 2. Using in-situ polymerization technology, specially surface-treated TiO2 is directly introduced into the polyester polymerization system. In-situ dispersion technology evenly distributes it between polyester molecular chains. Adjusting the polycondensation temperature, vacuum level, and stirring speed ensures uniform distribution of the TiO2 without affecting molecular weight growth, enabling the preparation of polyester with ultra-high TiO2 content. This technology overcomes the limitations of traditional finishing methods, making the functional component an inherent property of the fiber, resulting in advantages such as strong durability and stable performance.

[0027] 3. Ultra-high TiO2+tuck structure, the high refractive index of nano-TiO2 (2.4-2.9) can scatter visible light, reduce the optical contrast between sweat stains and fiber matrix, ensure smooth air circulation of the fabric, and make the fabric have excellent moisture absorption and quick-drying properties, which can make moisture evaporate quickly, improve the air permeability and wicking effect of the fabric, and can quickly conduct water vapor from the inside of the fabric to the outside of the fabric, and achieve a better sweat-hiding effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of the triangle arrangement and knitting needle arrangement of the present invention;

[0029] Figure 2 Schematic diagram of the triangle arrangement and knitting needle arrangement of the present invention;

[0030] Figure 3 Schematic diagram of the triangle arrangement and knitting needle arrangement of the present invention;

[0031] Figure 4 This is a schematic diagram of a water drop experiment of the developed fabric 1 prepared by the present invention;

[0032] Figure 5 Schematic diagram of a water drop experiment on the developed fabric 2 prepared by the present invention;

[0033] Figure 6 Schematic diagram of a water drop experiment on the developed fabric 3 prepared by the present invention;

[0034] Figure 7 Schematic diagram of the water drop experiment for comparison fabric 1;

[0035] Figure 8 Schematic diagram of the water drop experiment for comparison fabric 2. DETAILED DESCRIPTION

[0036] A method for preparing high-content titanium dioxide fiber and sweat-resistant knitted fabric adopts two-stage surface modification to achieve multi-level surface functionalization of TiO2 powder.

[0037] In the first stage, TiO2 particles were subjected to primary hydrophobic treatment by silane couple KH-550 (3-aminopropyltriethoxysilane (APTES));

[0038] The reaction process is as follows: reaction temperature 60-70°C, reaction time 2-4 hours, APTES / TiO2 mass ratio 1:10-1:15, accelerating silane hydrolysis and condensation reaction, ensuring monolayer coverage, and avoiding polymers.

[0039] The main purpose is to form a covalent bond between the siloxane group (-Si-O-) of the silane coupling agent and the hydroxyl group (-OH) on the surface of TiO2 through hydrolysis condensation reaction, with a coverage rate of more than 90%.

[0040] Charge regulation: Under acidic conditions of pH = 4-6, the surface potential of APTES-modified TiO2 is adjusted from -30mV to +15mV, providing electrostatic drive for subsequent dispersant adsorption.

[0041] In the second stage, the block copolymer PEO-PPO-PEO dispersant was introduced. PEO-PPO-PEO is composed of polyethylene oxide (PEO) and polypropylene oxide (PPO) blocks to form a synergistic effect of steric hindrance and electrostatic repulsion to inhibit the agglomeration of powders.

[0042] The reaction process is as follows: PEO-PPO-PEO is added dropwise to the premixed system to prevent flocculation caused by excessive local concentration, the pH of the system is controlled at 7.5-8.5 to promote the ionization of PEO chain segments, and the shear rate is 8000-12000 rpm to break the soft agglomerates and achieve uniform dispersion.

[0043] The main purpose is: Anchoring adsorption: The hydrophobic PPO chain segment of the copolymer is combined with the APTES hydrophobic layer through van der Waals force, and the hydrophilic PEO chain segment extends outward to form a "polymer brush" with a thickness of about 5-10nm.

[0044] Dual stabilization mechanism:

[0045] 1. Steric hindrance: The extended conformation of the PEO chain prevents the particles from approaching (critical distance ≈ 2 times the thickness of the polymer layer);

[0046] 2. Electrostatic repulsion: The carboxylic acid group (-COOH) at the end of PEO ionizes at pH>7 (zeta potential -25mV), enhancing the repulsive force between particles.

[0047] Using in-situ polymerization technology, TiO2 that has undergone two-stage surface modification is directly introduced into the polyester polymerization system. By adding PTA (3 mol), EG (5.4 mol) and TiO2 (0.07 mol) to the 3L polycondensation reaction, PET resin is directly prepared by esterification at a temperature of 230-260°C and a pressure of 0.3-0.5MPa. Through in-situ dispersion technology, it is evenly distributed between the polyester molecular chains, realizing the preparation of polyester with ultra-high TiO2 content.

[0048] The prepared ultra-high TiO2 content polyester is spun into POY through polyester spinning, and then stretched into ultra-high TiO2 content 50D / 36FDTY and 75D / 36F DTY.

[0049] Develop two types of tuck weave fabrics (weaving scheme 1 and weaving scheme 2 below) and one type of jersey weave fabric (weaving scheme 3 below).

[0050] Weaving scheme 1:

[0051] The tuck mesh structure is woven on a 30" 28G double-sided machine to develop a tuck weave fabric. The weaving process is as follows:

[0052] The 30" 28G double-sided knitting machine is used to complete the process: the yarn arrangement is as follows: ①③⑤⑦ are all 75D / 36FDTY with ultra-high TiO2 content, the line length is 15.6cm / 50N, and the yarn feeding ratio is 45%; ②④⑥⑧ are all 50D / 36F DTY with ultra-high TiO2 content, the line length is 13cm / 50N, and the yarn feeding ratio is 56.19%. The needle arrangement is 1212, the front side is a full-needle sweat fabric, and the back side forms a tuck-loop breathable and moisture-conducting groove structure. The triangle arrangement and the needle arrangement are as follows Figure 1 shown.

[0053] Weaving scheme 2:

[0054] The tuck mesh structure is woven on a 34" 28G double-sided machine to develop a tuck weave fabric. The weaving process is as follows:

[0055] Use 34" 28G double-sided machine to complete: the yarn arrangement method is: ①③⑤⑦⑨ All are ultra-high TiO2 content 75D / 36FDTY, wire length is 12.3cm / 50N, yarn eating ratio is 45.62%, ②④⑥⑧⑩ All are ultra-high TiO2 content 50D / 36FDTY, the line length is 12.3cm / 50N, the yarn feeding ratio is 54.38%, the needle arrangement is: 12 1213, the front is a full needle jersey, and the back forms a tuck loop breathable and moisture-conducting groove structure. Figure 2 shown.

[0056] Weaving scheme three:

[0057] Using 30" 28G large circular knitting machine, ultra-high TiO2 content 75D / 36F DTY, to develop jersey fabric. The weaving triangle sorting is as follows Figure 3 shown.

[0058] Control group 1:

[0059] The same weaving structure and dyeing and finishing process as weaving scheme 1 are used. The difference lies in the yarn. The ultra-high TiO2 content DTY is replaced with full-dull DTY of the same specification.

[0060] Control group 2:

[0061] The same weaving structure and dyeing and finishing process as weaving scheme three are adopted. The difference is that the ultra-high TiO2 content DTY of the yarn is replaced with the full-dull DTY of the same specification.

[0062] Dyeing and finishing process design and production

[0063] The overall process of dyeing and finishing: cloth sorting → pretreatment → dyeing → reduction cleaning → softening in the bath → shaping and finishing → finished product inspection.

[0064] Considering hidden perspiration stains is mainly based on the following mechanisms:

[0065] 1. Optical shielding mechanism: The high refractive index of nano-TiO2 (2.4-2.9) can scatter visible light and reduce the optical contrast between sweat stains and fiber matrix.

[0066] 2. Surface energy regulation: Changes in the surface energy of TiO2-modified fibers affect the spreading behavior of sweat, forming a more uniform liquid film rather than local accumulation.

[0067] 3. Rapid drying effect: The photocatalytic activity of TiO2 promotes the decomposition of organic matter in sweat and accelerates the evaporation process.

[0068] Performance indicators

[0069] Hygroscopicity was tested according to GB / T 21655.1-2023, "Assessment of Moisture Absorption and Quick-Drying Properties of Textiles." Hidden perspiration stains were assessed using visual inspection with a drop of water and color difference values ​​according to GB / T 8424.3-2001, "Textiles - Tests for Colour Fastness - Calculation of Colour Difference." The performance of the development and control fabrics is shown in Table 1.

[0070] Table 1 Moisture absorption, quick drying and hidden sweat stain performance of developed fabrics and control fabrics

[0071]

[0072] Figure 4 The experiment of 1 drop of water on the developed fabric is shown respectively, with 1 drop of water on each side, taking a photo for 5 seconds, and flipping the fabric for 10 seconds; Figure 5 The two water drop experiments on the developed fabric are shown respectively: one drop of water is added to each side, the photo is taken after 5 seconds, and the fabric is turned over after 10 seconds; Figure 6 The three-drop water experiment of the developed fabric is shown respectively, with one drop of water on each side, taking a photo for 5 seconds, and flipping the fabric for 10 seconds; Figure 7 The comparison fabric 1 drop of water experiment is shown respectively, with 1 drop of water on each side, 5 seconds to take a photo, and the fabric flipped over for 10 seconds; Figure 8 Two water drop experiments on the comparison fabric are shown respectively, with 1 drop of water on each side, taking a photo for 5 seconds, and flipping the fabric for 10 seconds.

[0073] Moisture absorption and quick-drying tests showed that fabrics with ultra-high TiO2 content exhibited excellent breathability and moisture conduction, with tucked fabrics performing better than jersey fabrics. The tucked fabric design and vent structure allow for rapid moisture evaporation, improving the fabric's breathability and wicking properties. The standard polyester tucked fabric control group 1 and standard polyester jersey control group 2 exhibited poor breathability and moisture conduction. The developed fabric exhibited excellent resistance to hidden sweat stains, while the control group exhibited poor resistance.

Claims

1. A method for preparing high-content titanium dioxide fiber and sweat-resistant knitted fabric, characterized in that: The steps include: Step S1: firstly perform primary hydrophobic treatment on TiO2 particles by using silane couple KH-550; Step S2: introducing a block copolymer PEO-PPO-PEO dispersant to form a steric hindrance and electrostatic repulsion synergistic effect to inhibit powder agglomeration; Step S3: Using in-situ polymerization technology, the TiO2 that has undergone the above-mentioned surface modification treatment is directly introduced into the polyester polymerization system. PTA, EG, and TiO2 are added to the 3L polycondensation reaction and then directly esterified at a temperature of 230-260°C and a pressure of 0.3-0.5 MPa to prepare PET resin. The TiO2 is evenly distributed between the polyester molecular chains through an in-situ dispersion technology to prepare a polyester with ultra-high TiO2 content. Step S4: The ultra-high TiO2 content polyester prepared in step S3 is spun into POY by polyester spinning, and then subjected to stretching to produce ultra-high TiO2 content 50D / 36F DTY and 75D / 36F DTY; Step S5: Develop two tuck weave fabrics and one jersey weave fabric.

2. The method for preparing high-content titanium dioxide fiber and hidden sweat-staining knitted fabric according to claim 1, characterized in that: The silane couple KH-550 in step S1 is 3-aminopropyltriethoxysilane.

3. The method for preparing high-content titanium dioxide fiber and hidden sweat-staining knitted fabric according to claim 2, characterized in that: The reaction process of step S1 is: The reaction temperature is 60-70°C, the reaction time is 2-4 hours, and the mass ratio of 3-aminopropyltriethoxysilane to TiO2 is 1:10-1:15, which accelerates the hydrolysis and condensation reaction of silane; The charge regulation of step S1 is as follows: under acidic conditions of pH = 4-6, the surface potential of TiO2 modified with 3-aminopropyltriethoxysilane is adjusted from -30 mV to +15 mV, providing electrostatic drive for subsequent dispersant adsorption.

4. The method for preparing high-content titanium dioxide fiber and hidden sweat-staining knitted fabric according to claim 1, characterized in that: The PEO-PPO-PEO dispersant in step S2 is composed of polyethylene oxide and polypropylene oxide blocks.

5. The method for preparing high-content titanium dioxide fiber and hidden sweat-staining knitted fabric according to claim 4, characterized in that: The reaction process of step S2 is: Add PEO-PPO-PEO dispersant dropwise to the premixed system, control the pH of the system to 7.5-8.5 to promote the ionization of PEO segments, and the shear rate to 8000-12000 rpm; Anchoring adsorption: The hydrophobic PPO chain segment of the copolymer is bound to the hydrophobic layer of 3-aminopropyltriethoxysilane through van der Waals force, and the hydrophilic PEO chain segment extends outward to form a "polymer brush" with a thickness of 5-10nm.

6. The method for preparing high-content titanium dioxide fiber and hidden sweat-staining knitted fabric according to claim 1, characterized in that: In step S3, PTA is 3 mol, EG is 5.4 mol, and TiO2 is 0.07 mol.

7. The method for preparing high-content titanium dioxide fiber and hidden sweat-staining knitted fabric according to claim 1, characterized in that: The tuck mesh structure is woven using a 30" 28G double-sided machine to develop a tuck weave fabric. The weaving process is as follows: The yarn arrangement is completed using a 30" 28G double-sided machine: ①③⑤⑦ are all 75D / 36FDTY with ultra-high TiO2 content, with a line length of 15.6cm / 50N and a yarn feeding ratio of 45%; ②④⑥⑧ are all 50D / 36F DTY with ultra-high TiO2 content, with a line length of 13cm / 50N and a yarn feeding ratio of 56.19%. The needle arrangement is 1212, with the front side being a full-needle jersey and the back side forming a tucked-in, breathable, and moisture-conducting groove structure.

8. The method for preparing high-content titanium dioxide fiber and hidden sweat-staining knitted fabric according to claim 1, characterized in that: The 34" 28G double-sided machine is used to weave the tuck mesh structure and develop the tuck structure fabric; the yarn arrangement method is: ①③⑤⑦⑨ All are ultra-high TiO2 content 75D / 36F DTY, wire length is 12.3cm / 50N, yarn eating ratio is 45.62%, ②④⑥⑧⑩ They are all 50D / 36F DTY with ultra-high TiO2 content, with a line length of 12.3cm / 50N, a yarn feeding ratio of 54.38%, and a needle arrangement method of 12 1213. The front side is a full-needle jersey fabric, and the back side forms a loop-shaped breathable and moisture-conducting groove structure.

9. The method for preparing high-content titanium dioxide fiber and hidden sweat-staining knitted fabric according to claim 1, characterized in that: Using 30” 28G large circular knitting machine, ultra-high TiO2 content 75D / 36F DTY, to develop jersey fabric.

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