A preparation method of a fabric for original yarn sunscreen clothing

Abstract

The present invention belongs to the fields of materials science and textile technology, and relates to a preparation method of a fabric for sunscreen clothing with raw yarns. Spinning is carried out on a spinning melt containing 12-15 wt% of coated and modified titanium dioxide. During the spinning process, a draw ratio of 5-6 times is carried out. After obtaining the sunscreen fibers, the sunscreen fibers are spun into sunscreen yarns, and then the sunscreen yarns are woven into a fabric, thus obtaining the fabric for sunscreen clothing with raw yarns. The coated and modified titanium dioxide includes titanium dioxide and a polyester oligomer coated on its surface through a covalent bond. The polyester oligomer and the matrix of the spinning melt only differ in the average degree of polymerization. The spinning uses a hollow profiled spinneret. The fabric for sunscreen clothing with raw yarns prepared by the present invention has good ultraviolet resistance, air permeability, moisture permeability and comfortable wearing performance.

Description

Technical Field

[0001] The present invention belongs to the fields of materials science and textile technology, and relates to a preparation method of a fabric for original yarn sunscreen clothing. Background Art

[0002] With the prevalence of outdoor sports and the improvement of people's living standards, sunscreen clothing, as an important equipment to protect the skin from ultraviolet damage, has an increasing market demand. The functionality of sunscreen clothing is mainly reflected in its anti-ultraviolet ability, and the existing sunscreen clothing mainly achieves the sunscreen effect by coating an anti-ultraviolet coating on the fabric surface. However, although this method can effectively block ultraviolet rays, it often sacrifices the air permeability and moisture permeability of the fabric, making the wearer feel stuffy and uncomfortable in the hot summer. After sweating a lot, the clothes are easy to stick to the body, reducing the wearing comfort and sunscreen effect.

[0003] Currently, most common fabrics for sunscreen clothing use synthetic fibers such as polyester, and achieve the purpose of sunscreen by adding an anti-ultraviolet coating during the post-finishing process. For example, patent application CN202221956910.3 discloses an outdoor water-repellent antibacterial sunscreen clothing fabric, and the sunscreen function of this fabric comes from the anti-ultraviolet coating coated on the fabric surface. Similarly, patent applications CN202021370938.X and CN202121910647.X also achieve the sunscreen function by coating an anti-ultraviolet coating respectively. Although the sunscreen effects of these fabrics are remarkable, their air permeability and moisture permeability are poor, and the wearing experience is not good.

[0004] In order to improve the air permeability and moisture permeability of sunscreen clothing, patent application CN202222192491.7 discloses a profiled fiber monofilament, profiled yarn, sunscreen fabric and sunscreen clothing. The cross-section of the used profiled fiber monofilament is a structure of three juxtaposed quasi-circular shapes to increase the air permeability and moisture absorption of the fabric. However, the anti-ultraviolet ability of this profiled fiber is relatively weak, and it is difficult to meet the high requirements of people for sunscreen clothing in the hot summer.

[0005] Therefore, there is an urgent need for a fabric that can simultaneously have good anti-ultraviolet performance and air permeability and moisture permeability to meet people's needs for sunscreen clothing. Summary of the Invention

[0006] The purpose of the present invention is to solve the problems existing in the prior art and provide a preparation method of a fabric for original yarn sunscreen clothing.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0008] A preparation method of a fabric for original yarn sunscreen clothing. Spinning is carried out on a spinning melt containing 12 - 15wt% of coated and modified titanium dioxide. During the spinning process, a draw ratio of 5 - 6 times is carried out. After obtaining the sunscreen fibers, the sunscreen fibers are spun into sunscreen yarns, and then the sunscreen yarns are woven into a fabric, thus obtaining the fabric for original yarn sunscreen clothing;

[0009] The D50 particle size (i.e., median diameter or median particle size) of the coated and modified titanium dioxide is 50 - 900nm;

[0010] The coated and modified titanium dioxide includes titanium dioxide and a polyester oligomer coated on its surface through a covalent bond. The polyester oligomer and the matrix of the spinning melt only have different average degrees of polymerization. The average degree of polymerization of the polyester oligomer is 20 - 60;

[0011] The spinning uses a hollow profiled spinneret.

[0012] As a preferred technical solution:

[0013] For the preparation method of the fabric for original yarn sunscreen clothing as described above, the thickness of the polyester oligomer on the surface of titanium dioxide is 10 - 100nm.

[0014] For the preparation method of the fabric for original yarn sunscreen clothing as described above, the preparation method of the coated and modified titanium dioxide is: first, titanium dioxide is organically modified with a coupling agent to obtain coupling agent - modified titanium dioxide, and at the same time, a polyester oligomer is prepared. Then, the polyester oligomer and the coupling agent - modified titanium dioxide are mixed and reacted.

[0015] For the preparation method of the fabric for original yarn sunscreen clothing as described above, the coupling agent is γ - aminopropyltriethoxysilane or γ - aminopropyltrimethoxysilane; the mass of the coupling agent is 3 - 5% of the mass of titanium dioxide; the organic modification is completed in a high - speed blender with a rotation speed of 2500 - 3000r / min, a temperature of 80 - 100°C, and a time of 2 - 3h.

[0016] For the preparation method of the fabric for original yarn sunscreen clothing as described above, the preparation steps of the coated and modified titanium dioxide are as follows:

[0017] (a) Organically modify titanium dioxide with a coupling agent to obtain coupling agent - modified titanium dioxide;

[0018] (b) Add a dibasic acid and a diol to a reaction kettle, stir and heat up to 200 - 230°C, and control the pressure of the reaction system to 0.2 - 0.3MPa. After reacting for 3 - 5h, add a catalyst, control the reaction system to gradually heat up to 260 - 270°C, and evacuate to a vacuum degree lower than 80Pa. After reacting for 2 - 3h, then cool down to 230°C to obtain the polyester oligomer;

[0019] (c) Add coupling agent - modified titanium dioxide to the reaction system of step (b), stir to mix it evenly, keep the temperature for reaction for 0.5 - 1 h, continuously evacuate, discharge, cool, pre - crush, and then perform air - flow crushing to obtain coated and modified titanium dioxide;

[0020] The dibasic acid is terephthalic acid; the dihydric alcohol is one or more of ethylene glycol, propylene glycol, and butanediol.

[0021] For the preparation method of the raw - yarn sunscreen clothing fabric as described above, the molar ratio of dibasic acid to dihydric alcohol is 1:0.9 - 0.95; the mass of the catalyst is 0.01 - 0.1% of the mass of the dibasic acid; the mass ratio of coupling agent - modified titanium dioxide to polyester oligomer is 5 - 8:1.

[0022] For the preparation method of the raw - yarn sunscreen clothing fabric as described above, the process for preparing the spinning melt is as follows: First, melt - blend resin A with coated and modified titanium dioxide to obtain a masterbatch with a concentration of 50 - 65 wt%, and then melt - blend the masterbatch with resin B through a single - screw extruder to obtain the spinning melt. Among them, resin A and resin B are the same substance, the length - to - diameter ratio of the screw is 25 - 30:1, and the temperature from the first zone to the fifth zone of the single - screw extruder is 240 - 280 °C.

[0023] For the preparation method of the raw - yarn sunscreen clothing fabric as described above, the production process flow of the sunscreen fiber is: the spinning melt is extruded from a hollow - shaped spinneret → primary cooling → primary winding → secondary cooling → oiling → drawing → false - twist texturing → heat setting → secondary winding;

[0024] The cold air temperature used for primary cooling is 15 - 25 °C; the speed of primary winding is 800 - 1200 m / min; secondary cooling means storing for 24 h under the conditions of a temperature of 20 - 30 °C and a relative humidity of 60 - 70%; the concentration of the oil agent used for oiling is 10 - 18 wt%, and the rotational speed of the oil roller is 4 - 6 revolutions per minute; the drawing speed is 780 - 850 m / min, and the drawing temperature is 80 - 120 °C; false - twist texturing is carried out on a texturing machine, the speed ratio (D / Y) is 1.5 - 1.7, the temperature of the first hot box is 150 - 180 °C, the temperature of the second hot box is 120 - 130 °C; the heat - setting temperature is 135 - 145 °C; the speed of secondary winding is 4500 - 4600 m / min.

[0025] For the preparation method of the raw - yarn sunscreen clothing fabric as described above, the specification of the sunscreen fiber is 20 - 50 D / 12 - 36 F; the specification of the sunscreen yarn is 20 - 50 metric counts; the raw - yarn sunscreen clothing fabric is a knitted fabric, the number of needles of the circular knitting machine is 40 G, and the gram weight is 150 - 300 g / m 2; alternatively, the fabric for the original yarn sunscreen clothing is a woven plain fabric, with a warp density of 120 - 130 threads / 10 cm, a weft density of 130 - 150 threads / 10 cm, and a gram weight of 40 - 300 g / m 2 ; alternatively, the fabric for the original yarn sunscreen clothing is a woven twill fabric, with a warp density of 120 - 190 threads / 10 cm, a weft density of 140 - 150 threads / 10 cm, and a gram weight of 60 - 300 g / m 2 ; the UPF value of the fabric for the original yarn sunscreen clothing is 50 - 1300, the change rate of the UPF value after 30 washes is not higher than 5%, the water droplet diffusion time is 1 - 2 s, the water absorption rate is 105 - 120%, the maximum diffusion radius is 25 - 30 mm, the diffusion speed > 4 mm / s, and the rising rate of the 100% water-containing tensile force (used to characterize the viscosity between the fabric in the wet state and the skin) does not exceed 20%.

[0026] Principle of the invention:

[0027] During the preparation of the hollow profiled fiber of the present invention, the coated and modified titanium dioxide with a specific particle size is densely distributed in the resin matrix. During the spinning process, the fiber undergoes high-fold drawing (5 - 6 times). While the fiber is being refined, the coated and modified titanium dioxide is squeezed against each other during the fiber drawing process, and the coated and modified titanium dioxide aggregates and exposes towards the inner surface and the outer surface of the hollow fiber respectively, thereby forming a large number of convex structures on the inner surface and the outer surface of the fiber (as Figure 1 shown), and these convex structures are similar to a dot array.

[0028] For the outer surface of the hollow profiled fiber, a large number of convex structures cause most of the light to fall on the convexes. The convexes are formed by the coated and modified titanium dioxide. Since the coated and modified titanium dioxide has a strong scattering effect on ultraviolet rays, most of the ultraviolet rays can be scattered by the coated and modified titanium dioxide and cannot irradiate the human skin, and the ultraviolet rays that are not scattered will enter the hollow profiled fiber. Since a large number of convex structures are also distributed on the inner surface of the hollow profiled fiber, the ultraviolet rays entering the hollow profiled fiber will further scatter and reflect on the inner surface of the hollow profiled fiber. The scattered part of the ultraviolet rays cannot pass through the fabric to reach the human skin, and the reflected part will be scattered again among the coated and modified titanium dioxides inside the hollow profiled fiber, thereby endowing the hollow profiled fiber with the original yarn sunscreen function.

[0029] Meanwhile, the hollow profiled fibers of the present invention can be used to obtain the original yarn sunscreen fabric through weaving. For the inner side of the fabric, a large number of convex structures on the outer surface of the hollow profiled fibers can reduce the contact area when the fabric contacts the skin, prevent the fabric from sticking to the skin when sweating profusely, causing discomfort to the body. At the same time, a large number of grooves are formed between the protrusions on the surface of the same hollow profiled fiber, which is conducive to the rapid spreading of water on the fiber surface. A large number of capillary-like channels are formed between the protrusions of different hollow profiled fibers, which is conducive to the rapid conduction of water, further improving the moisture conduction function of the fabric, making the fabric achieve the functions of being wet but not sticky, waterproof and quick-drying, and greatly enhancing the comfort of the human body.

[0030] Beneficial effects:

[0031] (1) A large amount of coated modified titanium dioxide is introduced into the hollow profiled fibers of the present invention. By means of the strong scattering effect of titanium dioxide on ultraviolet rays, it can effectively block ultraviolet rays from irradiating the human skin. At the same time, through the coating modification of titanium dioxide, titanium dioxide is not easily lost during the washing process, ensuring that the UPF value of the fabric does not change significantly after multiple washes, achieving long-lasting sun protection.

[0032] (2) For the hollow profiled fibers of the present invention and the fabric woven therefrom, since a large number of convex structures are distributed on both the inner and outer surfaces of the fibers, not only the anti-ultraviolet performance is enhanced, but also the air permeability and moisture permeability of the fabric are significantly improved. When worn, the fabric can quickly absorb and disperse sweat, keep the skin dry, improve the wearing comfort, and has the characteristics of being wet but not sticky, waterproof and quick-drying. Even when sweating profusely, the fabric will not stick tightly to the skin. Brief description of the drawings

[0033] Figure 1 It is a schematic structural diagram of the sunscreen fiber of Example 1; wherein, a is the cross-section and b is the profile. Detailed implementation manners

[0034] The present invention will be further described below in conjunction with specific implementation manners. It should be understood that these examples are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0035] The following are the test methods for relevant performance indicators in each example and comparative example:

[0036] Average degree of polymerization: It is tested by gel permeation chromatography (GPC).

[0037] UPF value: It is tested with reference to GB / T 18830-2009.

[0038] Washing: Test according to GB / T 8629-2001.

[0039] Water droplet diffusion time: Test according to the water droplet diffusion time in 8.2 of GB / T 21655.1-2023.

[0040] Water absorption rate: Test according to the water absorption rate detection method in 8.1 of GB / T 21655.1-2023.

[0041] Maximum diffusion radius, diffusion speed: Cut the sample to be tested into sheet specimens of 10 cm×10 cm, conduct a water dripping experiment according to 8.21-8.23 in GB / T21655.1-2023. Start timing from the moment the water droplet touches the surface of the specimen (recorded as t0, unit: s), and stop timing when the outermost side of the wetting circle of the water on the specimen stops spreading (recorded as t, unit: s). Measure the distances from 3 different points on the outermost side of the wetting circle to the center point within 30 s. The arithmetic mean of the 3 values is recorded as the maximum diffusion radius (unit: mm); diffusion speed = maximum diffusion radius / (t - t0).

[0042] 100% water content tensile strength increase rate: Cut the sample to be tested, prepare 6 sheet specimens of 20 cm×5 cm, divide them into group A and group B, with 3 specimens in each group. Conduct water content treatment on the specimens in group A and group B under the conditions of temperature 29℃±0.2℃ and environmental humidity 65%±2%: The specimens in group A are respectively treated with 100% water content, and the specimens in group B are respectively treated with 0% water content; The specific process of 100% water content treatment is: Use a humidifier to continuously humidify the specimens until the mass of the fabric increases by 100% of its original mass; The specific process of 0% water content treatment is: Put the specimens into a vacuum drying oven at 60℃ for drying until the water content of the specimens is 0%;

[0043] Subsequently, test the 100% water content tensile strength and 0% water content tensile strength respectively. The specific process is: Select a subject, use a marker pen to mark two marking lines on the subject's forearm (at positions 5 cm and 10 cm from the elbow). Use iron clips to clamp the two short sides of the fabric specimen respectively. The subject keeps the forearm horizontal, place the specimen between the two drawn marking lines, and let the two ends of the specimen hang naturally. Then, hang a 25 g weight on one end of the specimen and connect a spring scale to the other end. After adjusting the spring scale to zero, slowly pull the spring scale until the specimen starts to slide on the forearm. At the moment when the specimen slides, quickly record the tensile force data on the spring scale. The average value of the tensile force data of the specimens in group A is the 100% water content tensile strength (recorded as F 100% , unit: N), and the average value of the tensile force data of the specimens in group B is the 0% water content tensile strength (recorded as F 0%, unit N); all tests were completed on the arm of the same subject, and the subject's arm was dried between each test;

[0044] Finally, calculate the 100% water-containing tensile increase rate of the sample to be tested through the following formula:

[0045] 100% water-containing tensile increase rate = (F 100% - F 0% ) / F 0% .

[0046] Example 1

[0047] A preparation method of a fabric for original yarn sunscreen clothing, the specific steps are as follows:

[0048] (1) Preparation of raw materials;

[0049] Coupling agent: γ-aminopropyltriethoxysilane;

[0050] Titanium dioxide;

[0051] Dicarboxylic acid: terephthalic acid;

[0052] Diol: ethylene glycol;

[0053] Catalyst: antimony glycolate;

[0054] Resin A and Resin B: both are polyesters (PET) with an average degree of polymerization of 600;

[0055] (2) Preparation of coated and modified titanium dioxide;

[0056] (2.1) In a high-speed blender, under the conditions of a rotation speed of 3000 r / min and a temperature of 80 °C, the titanium dioxide was organically modified with a coupling agent for 2.5 h to obtain coupling agent-modified titanium dioxide; among them, the mass of the coupling agent was 5% of the mass of the titanium dioxide;

[0057] (2.2) Add the dicarboxylic acid and diol to the reaction kettle, stir and heat up to 200 °C, and control the pressure of the reaction system to 0.2 MPa, then react for 4.5 h, then add the catalyst, control the reaction system to gradually heat up to 260 °C, and evacuate to 75 Pa, then react for 2.2 h, and then cool down to 230 °C to obtain a polyester oligomer with an average degree of polymerization of 20; among them, the molar ratio of the dicarboxylic acid to the diol was 1:0.95, and the mass of the catalyst was 0.01% of the mass of the dicarboxylic acid;

[0058] (2.3) Add coupling agent-modified titanium dioxide to the reaction system of step (2.2), stir to mix it evenly, keep the temperature for reaction for 0.5 h, continuously evacuate, discharge, cool, pre-crush, and air-crush to obtain coated and modified titanium dioxide; wherein, the mass ratio of the coupling agent-modified titanium dioxide to the polyester oligomer is 5:1;

[0059] The obtained coated and modified titanium dioxide includes titanium dioxide and polyester oligomer, and the polyester oligomer is coated on the surface of titanium dioxide through a coupling agent; the D50 particle size of the coated and modified titanium dioxide is 600 nm, and the thickness of the polyester oligomer on the surface of titanium dioxide is 60 nm;

[0060] (3) Prepare a spinning melt;

[0061] First, melt-blend resin A with the coated and modified titanium dioxide to obtain a masterbatch with a concentration of 55 wt%, and then melt-blend the masterbatch with resin B through a single-screw extruder to obtain a spinning melt containing 13 wt% of the coated and modified titanium dioxide; wherein, the length-diameter ratio of the screw is 25:1, and the temperatures of the single-screw extruder from zone 1 to zone 5 are 240 °C, 245 °C, 265 °C, 280 °C, and 280 °C in sequence;

[0062] (4) Prepare sunscreen fibers;

[0063] The production process flow of the sunscreen fibers is as follows: the spinning melt is extruded from a hollow profiled spinneret → cooled → wound for the first time → stored → oiled → drawn → false-twist deformed (performed on a texturing machine) → heat-set → wound for the second time;

[0064] The cold air temperature used for cooling is 15 °C; the speed of the first winding is 800 m / min; the storage temperature is 20 °C, the relative humidity during storage is 65%, and the storage time is 24 h; the concentration of the oil agent used for oiling is 12 wt%, and the rotational speed of the oil wheel is 5 revolutions per minute; the drawing speed is 780 m / min, the drawing temperature is 85 °C, and the drawing ratio is 5 times; the speed ratio of the false-twist deformation is 1.5, the temperature of the first hot box is 150 °C, and the temperature of the second hot box is 120 °C; the heat-setting temperature is 135 °C; the speed of the second winding is 4500 m / min;

[0065] The obtained sunscreen fibers have a specification of 20 D / 12 F, and the structure of the sunscreen fibers is as Figure 1 shown;

[0066] (5) Prepare the fabric for the original yarn sunscreen clothing;

[0067] Spun the sunscreen fibers into sunscreen yarns with a specification of 25 metric counts, and then weave the sunscreen yarns into a fabric to obtain the fabric for the original yarn sunscreen clothing.

[0068] The finally obtained fabric for the original yarn sunscreen clothing is a knitted fabric, with a circular knitting machine needle count of 40G and a gram weight of 150 g / m 2 ; The UPF value of the fabric for the original yarn sunscreen clothing is 260, the change rate of the UPF value after 30 washes is 2.2%, the water droplet diffusion time is 1.5 s, the water absorption rate is 118%, the maximum diffusion radius is 28.2 mm, the diffusion speed is 4.8 mm / s, and the rising rate of the 100% water-containing tensile force is 14.8%.

[0069] Comparative Example 1

[0070] A method for preparing a fabric is basically the same as that in Example 1, with the only difference being that: in the spun melt obtained in step (3), the content of the coated modified titanium dioxide is 10 wt%.

[0071] The finally obtained fabric has a UPF value of 80, a water droplet diffusion time of 2.8 s, a water absorption rate of 94%, a maximum diffusion radius of 17.3 mm, a diffusion speed of 2.4 mm / s, and a rising rate of the 100% water-containing tensile force of 86%.

[0072] Compared with Example 1, the anti-ultraviolet performance and breathable and moisture-permeable performance of the fabric in Comparative Example 1 are significantly reduced. This is because the addition amount of the coated modified titanium dioxide in Comparative Example 1 is too low, resulting in a low distribution density of the coated modified titanium dioxide in the resin matrix. During the drawing process, the degree of mutual extrusion between the particles is weak, and it is impossible to promote sufficient coated modified titanium dioxide to fully aggregate and expose on the inner and outer surfaces of the hollow profiled fiber, and thus it is difficult to form a raised structure similar to a dot array;

[0073] From the perspective of anti-ultraviolet performance, due to the insufficient number of raised structures on the outer surface, the proportion of light falling on the raised parts composed of the coated modified titanium dioxide is greatly reduced, and the effect of blocking ultraviolet rays by relying on the strong light scattering effect of the coated modified titanium dioxide is weakened, and more ultraviolet rays can penetrate the fabric, resulting in a decrease in the anti-ultraviolet ability of the fabric;

[0074] For the breathable and moisture-permeable performance, since the raised structures on the fiber surface are not rich enough, the number of grooves formed between the raised parts on the surface of the same hollow profiled fiber and the capillary-like channels formed between the raised parts of different hollow profiled fibers is limited. When a person sweats, the sweat cannot be effectively discharged in time, the breathable and moisture-permeable function of the fabric becomes poor, and the functions of being wet without sticking, anti-permeation, and quick-drying cannot be well achieved.

[0075] Comparative Example 2

[0076] A method for preparing a fabric is basically the same as that in Example 1, with the only difference being that: in step (2.3), the process parameters of pre-crushing and air-flow crushing are adjusted so that the D50 particle size of the coated modified titanium dioxide is 40 nm.

[0077] The UPF value of the finally obtained fabric is 120, the water droplet diffusion time is 2.6 s, the water absorption rate is 88%, the maximum diffusion radius is 13.5 mm, the diffusion speed is 2.2 mm / s, and the 100% water-containing tensile strength increase rate is 102%.

[0078] Compared with Example 1, the anti-ultraviolet performance and the air permeability and moisture permeability of the fabric in Comparative Example 2 are significantly decreased. This is because the particle size of the coated and modified titanium dioxide in Comparative Example 2 is too small, and it is difficult to orderly aggregate and expose to the inner and outer surfaces of the fiber under mutual extrusion during the drawing process to form a convex structure similar to a dot array, resulting in the deterioration of both the anti-ultraviolet performance and the air permeability and moisture permeability of the fabric.

[0079] Comparative Example 3

[0080] A method for preparing a fabric is basically the same as that in Example 1, except that: in step (4), the drawing ratio is 4.5 times.

[0081] The UPF value of the finally obtained fabric is 135, the water droplet diffusion time is 3.1 s, the water absorption rate is 86%, the maximum diffusion radius is 13.3 mm, the diffusion speed is 2.1 mm / s, and the 100% water-containing tensile strength increase rate is 108%.

[0082] Compared with Example 1, the anti-ultraviolet performance and the air permeability and moisture permeability of the fabric in Comparative Example 3 are significantly decreased. This is because the drawing in Comparative Example 3 is insufficient, and the force and effect of mutual extrusion between particles are poor, resulting in a reduction in the number of coated and modified titanium dioxide aggregated and exposed to the inner and outer surfaces of the fiber, and it is difficult to form a convex structure, resulting in the deterioration of both the anti-ultraviolet performance and the air permeability and moisture permeability of the fabric.

[0083] Comparative Example 4

[0084] A method for preparing a fabric is basically the same as that in Example 1, except that: the hollow profiled spinneret is replaced by a common round-hole spinneret.

[0085] The UPF value of the finally obtained fabric is 40, the water droplet diffusion time is 1.6 s, the water absorption rate is 108%, the maximum diffusion radius is 28.0 mm, the diffusion speed is 4.5 mm / s, and the 100% water-containing tensile strength increase rate is 15.2%.

[0086] Compared with Example 1, the anti-ultraviolet performance and the air permeability and moisture permeability of the fabric in Comparative Example 4 are significantly decreased. This is because the common round-hole spinneret used in Comparative Example 4 is difficult to make the coated and modified titanium dioxide with a specific particle size mutually extrude and aggregate and expose to the inner and outer surfaces during the spinning process to form a large number of convex structures (similar to a dot array), resulting in the deterioration of both the anti-ultraviolet performance and the air permeability and moisture permeability of the fabric.

[0087] Example 2

[0088] A preparation method of a fabric for original yarn sunscreen clothing, the specific steps are as follows:

[0089] (1) Preparation of raw materials;

[0090] Coupling agent: γ-aminopropyltriethoxysilane;

[0091] Titanium dioxide;

[0092] Dicarboxylic acid: terephthalic acid;

[0093] Diol: propylene glycol;

[0094] Catalyst: ethylene glycol antimony;

[0095] Resin A and Resin B: both are polyesters (PET) with an average degree of polymerization of 720;

[0096] (2) Preparation of coated and modified titanium dioxide;

[0097] (2.1) In a high-speed blender, under the conditions of a rotation speed of 2800 r / min and a temperature of 100 °C, the titanium dioxide is organically modified with a coupling agent for 2.8 h to obtain coupling agent-modified titanium dioxide; among them, the mass of the coupling agent is 3% of the mass of the titanium dioxide;

[0098] (2.2) Add the dicarboxylic acid and the diol to the reaction kettle, stir and heat up to 210 °C, and control the pressure of the reaction system to 0.2 MPa, then react for 3.5 h, then add the catalyst, control the reaction system to gradually heat up to 265 °C, and evacuate to 68 Pa, then react for 2.6 h, and then cool down to 230 °C to obtain a polyester oligomer with an average degree of polymerization of 32; among them, the molar ratio of the dicarboxylic acid to the diol is 1:0.92, and the mass of the catalyst is 0.04% of the mass of the dicarboxylic acid;

[0099] (2.3) Add the coupling agent-modified titanium dioxide to the reaction system in step (2.2), stir to make it fully mixed, keep the temperature for reaction for 0.5 h, continuously evacuate, discharge, cool, pre-crush, and air-flow crush to obtain coated and modified titanium dioxide; among them, the mass ratio of the coupling agent-modified titanium dioxide to the polyester oligomer is 6:1;

[0100] The prepared coated and modified titanium dioxide includes titanium dioxide and polyester oligomer, and the polyester oligomer is coated on the surface of the titanium dioxide through a coupling agent; the D50 particle size of the coated and modified titanium dioxide is 300 nm, and the thickness of the polyester oligomer on the surface of the titanium dioxide is 30 nm;

[0101] (3) Preparation of spinning melt;

[0102] First, melt-blend resin A with coated and modified titanium dioxide to obtain a masterbatch with a concentration of 52 wt%. Then, melt-blend the masterbatch with resin B through a single-screw extruder to obtain a spinning melt containing 13 wt% of coated and modified titanium dioxide. Among them, the length-diameter ratio of the screw is 28:1, and the temperatures of the single-screw extruder from zone 1 to zone 5 are 240 °C, 245 °C, 265 °C, 280 °C, and 280 °C in sequence.

[0103] (4)Prepare sunscreen fibers;

[0104] The production process flow of the sunscreen fibers is as follows: the spinning melt is extruded from a hollow profiled spinneret → cooled → wound for the first time → stored → oiled → drawn → false-twist deformed (performed on a texturing machine) → heat-set → wound for the second time;

[0105] The cold air temperature used for cooling is 20 °C; the winding speed for the first time is 850 m / min; the storage temperature is 20 °C, the relative humidity during storage is 60%, and the storage time is 24 h; the concentration of the oil agent used for oiling is 15 wt%, and the rotation speed of the oil wheel is 4 revolutions per minute; the drawing speed is 800 m / min, the drawing temperature is 80 °C, and the drawing ratio is 5.2 times; the speed ratio of false-twist deformation is 1.6, the temperature of the first hot box is 150 °C, and the temperature of the second hot box is 130 °C; the heat-setting temperature is 138 °C; the winding speed for the second time is 4550 m / min;

[0106] The specification of the obtained sunscreen fibers is 50D / 36F;

[0107] (5)Prepare the fabric for the original yarn sunscreen clothing;

[0108] Spin the sunscreen fibers into sunscreen yarns with a specification of 33 metric counts, and then weave the sunscreen yarns into a fabric, thus obtaining the fabric for the original yarn sunscreen clothing.

[0109] The finally obtained fabric for the original yarn sunscreen clothing is a knitted fabric, the number of needles of the circular knitting machine is 40G, and the gram weight is 300 g / m 2 ; The UPF value of the fabric for the original yarn sunscreen clothing is 390, the change rate of the UPF value after 30 washes is 3.4%, the water droplet diffusion time is 1.6 s, the water absorption rate is 109%, the maximum diffusion radius is 25.3 mm, the diffusion speed is 4.2 mm / s, and the rising rate of the 100% water-containing tensile strength is 9.5%.

[0110] Example 3

[0111] A preparation method for the fabric of the original yarn sunscreen clothing, the specific steps are as follows:

[0112] (1)Preparation of raw materials;

[0113] Coupling agent: γ-aminopropyltriethoxysilane;

[0114] Titanium dioxide;

[0115] Dicarboxylic acid: terephthalic acid;

[0116] Diol: ethylene glycol;

[0117] Catalyst: tetrabutyl titanate;

[0118] Resin A and Resin B: both are polyesters (PET) with an average degree of polymerization of 600;

[0119] (2) Preparation of coated and modified titanium dioxide;

[0120] (2.1) In a high-speed mixer, under the conditions of a rotation speed of 2500 r / min and a temperature of 100 °C, the titanium dioxide is organically modified with a coupling agent for 2 h to obtain coupling agent-modified titanium dioxide; among them, the mass of the coupling agent is 3.5% of the mass of the titanium dioxide;

[0121] (2.2) Add the dicarboxylic acid and the diol to the reaction kettle, stir and heat up to 220 °C, and control the pressure of the reaction system to 0.25 MPa, then react for 3 h, then add the catalyst, control the reaction system to gradually heat up to 270 °C, and evacuate to 72 Pa, then react for 2 h, and then cool down to 230 °C to obtain a polyester oligomer with an average degree of polymerization of 42; among them, the molar ratio of the dicarboxylic acid to the diol is 1:0.9, and the mass of the catalyst is 0.06% of the mass of the dicarboxylic acid;

[0122] (2.3) Add the coupling agent-modified titanium dioxide to the reaction system in step (2.2), stir to make it fully mixed, keep the temperature for reaction for 1 h, continuously evacuate, discharge, cool, pre-crush, and air-flow crush to obtain coated and modified titanium dioxide; among them, the mass ratio of the coupling agent-modified titanium dioxide to the polyester oligomer is 8:1;

[0123] The obtained coated and modified titanium dioxide includes titanium dioxide and polyester oligomer, and the polyester oligomer is coated on the surface of the titanium dioxide through a coupling agent; the D50 particle size of the coated and modified titanium dioxide is 150 nm, and the thickness of the polyester oligomer on the surface of the titanium dioxide is 10 nm;

[0124] (3) Preparation of spinning melt;

[0125] First, melt-blend Resin A and the coated and modified titanium dioxide to obtain a masterbatch with a concentration of 50 wt%, and then melt-blend the masterbatch and Resin B through a single-screw extruder to obtain a spinning melt containing 12 wt% of the coated and modified titanium dioxide; among them, the length-diameter ratio of the screw is 30:1, and the temperatures of the first to fifth zones of the single-screw extruder are 240 °C, 245 °C, 265 °C, 280 °C, and 280 °C in sequence;

[0126] (4) Preparation of sunscreen fiber;

[0127] The production process flow of the sunscreen fiber is as follows: the spinning melt is extruded from a hollow profiled spinneret → cooling → primary winding → storage → oiling → drawing → false twist texturing (performed on a texturing machine) → heat setting → secondary winding;

[0128] The cold air temperature used for cooling is 20°C; the speed of primary winding is 1200 m / min; the storage temperature is 25°C, the relative humidity during storage is 63%, and the storage time is 24 h; the concentration of the oil agent used for oiling is 10 wt%, and the rotational speed of the oil wheel is 5 revolutions per minute; the drawing speed is 820 m / min, the drawing temperature is 110°C, and the drawing ratio is 6 times; the speed ratio of false twist texturing is 1.6, the temperature of the first hot box is 165°C, and the temperature of the second hot box is 128°C; the heat setting temperature is 142°C; the speed of secondary winding is 4580 m / min;

[0129] The specification of the obtained sunscreen fiber is 30D / 24F;

[0130] (5) Prepare the fabric for original yarn sunscreen clothing;

[0131] Spin the sunscreen fiber into a sunscreen yarn with a specification of 46 metric counts, and then weave the sunscreen yarn into a fabric, thus obtaining the fabric for original yarn sunscreen clothing.

[0132] The finally obtained fabric for original yarn sunscreen clothing is a woven plain fabric, with a warp density of 120 ends / 10 cm, a weft density of 150 ends / 10 cm, and a gram weight of 40 g / m 2 ; The UPF value of the fabric for original yarn sunscreen clothing is 50, the change rate of the UPF value after 30 washes is 1.8%, the water droplet diffusion time is 1.8 s, the water absorption rate is 120%, the maximum diffusion radius is 29.4 mm, the diffusion speed is 5 mm / s, and the rising rate of the 100% water-containing tensile force is 15.7%.

[0133] Example 4

[0134] A preparation method of a fabric for original yarn sunscreen clothing, the specific steps are as follows:

[0135] (1) Preparation of raw materials;

[0136] Coupling agent: γ-aminopropyltrimethoxysilane;

[0137] Titanium dioxide;

[0138] Dicarboxylic acid: terephthalic acid;

[0139] Diol: butanediol;

[0140] Catalyst: tetrabutyl titanate;

[0141] Resin A and Resin B: both are polyesters (PET) with an average degree of polymerization of 720;

[0142] (2) Prepare coated and modified titanium dioxide;

[0143] (2.1) In a high-speed blender, under the conditions of a rotation speed of 2500 r / min and a temperature of 90 °C, use a coupling agent to organically modify titanium dioxide for 3 h to obtain coupling agent-modified titanium dioxide; among them, the mass of the coupling agent is 4.5% of the mass of titanium dioxide;

[0144] (2.2) Add dibasic acid and diol to the reaction kettle, stir and heat up to 230 °C, and control the pressure of the reaction system to 0.25 MPa, then react for 4 h, then add a catalyst, control the reaction system to gradually heat up to 270 °C, and evacuate to 78 Pa, then react for 2.8 h, and then cool down to 230 °C to obtain a polyester oligomer with an average degree of polymerization of 60; among them, the molar ratio of dibasic acid to diol is 1:0.93, and the mass of the catalyst is 0.1% of the mass of dibasic acid;

[0145] (2.3) Add the coupling agent-modified titanium dioxide to the reaction system in step (2.2), stir to make it fully mixed, keep the temperature for reaction for 1 h, continuously evacuate, discharge, cool, pre-crush, and air-crush to obtain coated and modified titanium dioxide; among them, the mass ratio of the coupling agent-modified titanium dioxide to the polyester oligomer is 6:1;

[0146] The obtained coated and modified titanium dioxide includes titanium dioxide and polyester oligomer, and the polyester oligomer is coated on the surface of titanium dioxide through a coupling agent; the D50 particle size of the coated and modified titanium dioxide is 50 nm, and the thickness of the polyester oligomer on the surface of titanium dioxide is 10 nm;

[0147] (3) Prepare spinning melt;

[0148] First, melt-blend resin A and coated and modified titanium dioxide to obtain a masterbatch with a concentration of 60 wt%, and then melt-blend the masterbatch and resin B through a single-screw extruder to obtain a spinning melt containing 13.5 wt% of coated and modified titanium dioxide; among them, the length-diameter ratio of the screw is 30:1, and the temperatures of the first to fifth zones of the single-screw extruder are 240 °C, 245 °C, 265 °C, 280 °C, and 280 °C in sequence;

[0149] (4) Prepare sunscreen fiber;

[0150] The production process flow of the sunscreen fiber is: the spinning melt is extruded from a hollow profiled spinneret → cooled → wound for the first time → stored → oiled → drawn → false-twist deformed (performed on a texturing machine) → heat-set → wound for the second time;

[0151] The cold air temperature used for cooling is 25°C; the speed of the first winding is 1000 m / min; the storage temperature is 25°C, the relative humidity during storage is 68%, and the storage time is 24 h; the concentration of the oil agent used for oiling is 15 wt%, and the rotation speed of the oil roller is 6 revolutions per minute; the drafting speed is 850 m / min, the drafting temperature is 120°C, and the drafting multiple is 6 times; the speed ratio of false twist texturing is 1.7, the temperature of the first hot box is 180°C, and the temperature of the second hot box is 130°C; the heat setting temperature is 145°C; the speed of the second winding is 4600 m / min;

[0152] The prepared sunscreen fiber has a specification of 20D / 12F;

[0153] (5)Prepare the fabric for original yarn sunscreen clothing;

[0154] Spun the sunscreen fiber into sunscreen yarn with a specification of 50 metric counts, and then weave the sunscreen yarn into a fabric to obtain the fabric for original yarn sunscreen clothing.

[0155] The finally obtained fabric for original yarn sunscreen clothing is a woven plain fabric, with a warp density of 130 ends / 10 cm, a weft density of 130 ends / 10 cm, and a gram weight of 300 g / m 2 ; The UPF value of the fabric for original yarn sunscreen clothing is 1100, the change rate of the UPF value after 30 washes is 3.9%, the water droplet diffusion time is 1.4 s, the water absorption rate is 107%, the maximum diffusion radius is 26.4 mm, the diffusion speed is 4.3 mm / s, and the rising rate of the 100% water-containing tensile force is 12.3%.

[0156] Example 5

[0157] A preparation method of a fabric for original yarn sunscreen clothing, the specific steps are as follows:

[0158] (1)Preparation of raw materials;

[0159] Coupling agent: γ-aminopropyltrimethoxysilane;

[0160] Titanium dioxide;

[0161] Dicarboxylic acid: terephthalic acid;

[0162] Diol: a mixture of ethylene glycol and propylene glycol with a molar ratio of 1:1;

[0163] Catalyst: antimony glycolate;

[0164] Resin A and Resin B: both are polyesters (PET) with an average degree of polymerization of 600;

[0165] (2)Prepare coated and modified titanium dioxide;

[0166] (2.1) In a high-speed mixer, under the conditions of a rotation speed of 3000 r / min and a temperature of 90 °C, the titanium dioxide is organically modified with a coupling agent for 2.5 h to obtain coupling agent-modified titanium dioxide; wherein, the mass of the coupling agent is 4% of the mass of the titanium dioxide;

[0167] (2.2) Add a dibasic acid and a diol into a reaction kettle, stir and heat up to 225 °C, and control the pressure of the reaction system to be 0.3 MPa. After reacting for 5 h, add a catalyst, control the reaction system to gradually heat up to 265 °C, and evacuate to 76 Pa, then react for 3 h, and then cool down to 230 °C to obtain a polyester oligomer with an average degree of polymerization of 56; wherein, the molar ratio of the dibasic acid to the diol is 1:0.91, and the mass of the catalyst is 0.08% of the mass of the dibasic acid;

[0168] (2.3) Add the coupling agent-modified titanium dioxide to the reaction system in step (2.2), stir to make it fully mixed, keep the temperature for reaction for 1 h, continuously evacuate, discharge, cool, pre-crush, and air-crush to obtain coated and modified titanium dioxide; wherein, the mass ratio of the coupling agent-modified titanium dioxide to the polyester oligomer is 5:1;

[0169] The obtained coated and modified titanium dioxide includes titanium dioxide and a polyester oligomer, and the polyester oligomer is coated on the surface of the titanium dioxide through a coupling agent; the D50 particle size of the coated and modified titanium dioxide is 750 nm, and the thickness of the polyester oligomer on the surface of the titanium dioxide is 50 nm;

[0170] (3) Prepare a spinning melt;

[0171] First, melt-blend resin A and the coated and modified titanium dioxide to obtain a masterbatch with a concentration of 65 wt%, and then melt-blend the masterbatch and resin B through a single-screw extruder to obtain a spinning melt containing 15 wt% of the coated and modified titanium dioxide; wherein, the ratio of the length to the diameter of the screw is 28:1, and the temperatures of the first to fifth zones of the single-screw extruder are 240 °C, 245 °C, 265 °C, 280 °C, and 280 °C in sequence;

[0172] (4) Prepare sunscreen fibers;

[0173] The production process flow of the sunscreen fibers is: the spinning melt is extruded from a hollow profiled spinneret → cooled → wound for the first time → stored → oiled → drawn → false-twist deformed (performed on a texturing machine) → heat-set → wound for the second time;

[0174] The cold air temperature used for cooling is 23°C; the speed of the first winding is 900 m / min; the storage temperature is 30°C, the relative humidity during storage is 70%, and the storage time is 24 h; the concentration of the oil agent used for oiling is 13 wt%, and the rotational speed of the oil roller is 5 revolutions per minute; the drafting speed is 800 m / min, the drafting temperature is 115°C, and the drafting multiple is 5.6 times; the speed ratio of false twist texturing is 1.5, the temperature of the first hot box is 170°C, and the temperature of the second hot box is 125°C; the heat setting temperature is 145°C; the speed of the second winding is 4600 m / min;

[0175] The prepared sunscreen fiber has a specification of 50D / 12F;

[0176] (5)Prepare the fabric for original yarn sunscreen clothing;

[0177] Spin the sunscreen fiber into sunscreen yarn with a specification of 30 metric counts, and then weave the sunscreen yarn into a fabric, thus obtaining the fabric for original yarn sunscreen clothing.

[0178] The finally obtained fabric for original yarn sunscreen clothing is a woven twill fabric, with a warp density of 120 ends / 10 cm, a weft density of 150 ends / 10 cm, and a gram weight of 60 g / m 2 ; The UPF value of the fabric for original yarn sunscreen clothing is 420, the change rate of the UPF value after 30 washes is 2.6%, the water droplet diffusion time is 1.2 s, the water absorption rate is 116%, the maximum diffusion radius is 29.8 mm, the diffusion speed is 5.2 mm / s, and the rising rate of the 100% water-containing tensile force is 18.9%.

[0179] Example 6

[0180] A preparation method for the fabric of original yarn sunscreen clothing, the specific steps are as follows:

[0181] (1)Preparation of raw materials;

[0182] Coupling agent: γ-aminopropyltrimethoxysilane;

[0183] Titanium dioxide;

[0184] Dicarboxylic acid: terephthalic acid;

[0185] Diol: a mixture of ethylene glycol and butanediol with a molar ratio of 1:1;

[0186] Catalyst: tetrabutyl titanate;

[0187] Resin A and Resin B: both are polyesters (PET) with an average degree of polymerization of 720;

[0188] (2)Prepare coated and modified titanium dioxide;

[0189] (2.1)In a high-speed blender, under the conditions of a rotational speed of 3000 r / min and a temperature of 85 °C, the titanium dioxide was organically modified with a coupling agent for 3 h to obtain coupling agent-modified titanium dioxide; wherein, the mass of the coupling agent was 4% of the mass of the titanium dioxide;

[0190] (2.2)The dibasic acid and dibasic alcohol were added to a reaction kettle, stirred and heated to 220 °C, and after controlling the pressure of the reaction system to 0.3 MPa, the reaction was carried out for 5 h. Then a catalyst was added, the reaction system was gradually heated to 260 °C, and the vacuum was pumped to 70 Pa, and then the reaction was carried out for 2.5 h. Then it was cooled to 230 °C to obtain a polyester oligomer with an average degree of polymerization of 39; wherein, the molar ratio of the dibasic acid to the dibasic alcohol was 1:0.95, and the mass of the catalyst was 0.05% of the mass of the dibasic acid;

[0191] (2.3)The coupling agent-modified titanium dioxide was added to the reaction system of step (2.2), stirred to mix it evenly, kept warm and reacted for 0.75 h, continuously pumped the vacuum, discharged the material, cooled, pre-crushed, and air-crushed to obtain coated and modified titanium dioxide; wherein, the mass ratio of the coupling agent-modified titanium dioxide to the polyester oligomer was 7:1;

[0192] The prepared coated and modified titanium dioxide included titanium dioxide and polyester oligomer, and the polyester oligomer was coated on the surface of the titanium dioxide through a coupling agent; the D50 particle size of the coated and modified titanium dioxide was 900 nm, and the thickness of the polyester oligomer on the surface of the titanium dioxide was 100 nm;

[0193] (3)Prepare a spinning melt;

[0194] First, resin A and the coated and modified titanium dioxide were melt-blended to obtain a masterbatch with a concentration of 63 wt%, and then the masterbatch and resin B were melt-blended through a single-screw extruder to obtain a spinning melt containing 14 wt% of the coated and modified titanium dioxide; wherein, the length-diameter ratio of the screw was 25:1, and the temperatures of the first to fifth zones of the single-screw extruder were 240 °C, 245 °C, 265 °C, 280 °C, and 280 °C in sequence;

[0195] (4)Prepare sunscreen fibers;

[0196] The production process flow of the sunscreen fibers was: the spinning melt was extruded from a hollow profiled spinneret → cooled → wound for the first time → stored → oiled → drawn → false-twist deformed (performed on a texturing machine) → heat-set → wound for the second time;

[0197] The cold air temperature used for cooling is 18°C; the speed of the first winding is 950 m / min; the storage temperature is 30°C, the relative humidity during storage is 65%, and the storage time is 24 h; the concentration of the oil agent used for oiling is 18 wt%, and the rotational speed of the oil roller is 4.5 revolutions per minute; the drafting speed is 790 m / min, the drafting temperature is 105°C, and the drafting multiple is 5.5 times; the speed ratio of false twist texturing is 1.7, the temperature of the first hot box is 175°C, and the temperature of the second hot box is 125°C; the heat setting temperature is 135°C; the speed of the second winding is 4500 m / min;

[0198] The specification of the prepared sunscreen fiber is 50D / 24F;

[0199] (5) Prepare the fabric for the original yarn sunscreen clothing;

[0200] Spun the sunscreen fiber into sunscreen yarn with a specification of 20 metric counts, and then wove the sunscreen yarn into a fabric, thus obtaining the fabric for the original yarn sunscreen clothing.

[0201] The finally prepared fabric for the original yarn sunscreen clothing is a woven twill fabric, with a warp density of 190 ends / 10 cm, a weft density of 140 ends / 10 cm, and a gram weight of 300 g / m 2 ; The UPF value of the fabric for the original yarn sunscreen clothing is 1300, the change rate of the UPF value after 30 washes is 4.2%, the water droplet diffusion time is 1.6 s, the water absorption rate is 105%, the maximum diffusion radius is 27.6 mm, the diffusion speed is 4.5 mm / s, and the rising rate of the 100% water-containing tensile force is 13.6%.

Claims

1. A method for preparing raw yarn sunscreen clothing fabric, characterized in that: Spinning a spinning melt containing 12-15 wt% of coated modified titanium dioxide, and performing 5-6 times drafting during the spinning process to obtain a sun-proof fiber, spinning the sun-proof fiber into a sun-proof yarn, and then weaving the sun-proof yarn into a fabric, thereby obtaining an original yarn sun-proof clothing fabric; The D50 particle size of the coated modified titanium dioxide is 50~900nm; The coated modified titanium dioxide includes titanium dioxide and polyester oligomers coated on the surface thereof by covalent bonds, wherein the polyester oligomers and the matrix of the spinning melt are different only in average degree of polymerization, and the average degree of polymerization of the polyester oligomers is 20-60; The preparation method of the coated modified titanium dioxide is as follows: firstly, a coupling agent is used to organically modify titanium dioxide to obtain coupling agent modified titanium dioxide, and polyester oligomer is prepared at the same time, and then the polyester oligomer and the coupling agent modified titanium dioxide are mixed and reacted; The preparation steps of coated modified titanium dioxide are as follows: (a) organically modifying titanium dioxide with a coupling agent to obtain coupling agent-modified titanium dioxide; (b) adding the dibasic acid and the diol into a reaction kettle, stirring and heating to 200-230° C., controlling the pressure of the reaction system to 0.2-0.3 MPa, reacting for 3-5 hours, then adding a catalyst, controlling the temperature of the reaction system to gradually rise to 260-270° C., evacuating to a vacuum degree of less than 80 Pa, reacting for 2-3 hours, and then cooling to 230° C. to obtain a polyester oligomer; (c) adding the coupling agent modified titanium dioxide to the reaction system of step (b), stirring to fully mix, keeping the temperature for reaction for 0.5 to 1 hour, continuously evacuating the vacuum, discharging, cooling, pre-crushing, and airflow crushing to obtain coated modified titanium dioxide; The dibasic acid is terephthalic acid; the diol is one or more of ethylene glycol, propylene glycol and butanediol; The molar ratio of the dibasic acid to the diol is 1:0.9-0.95; the mass of the catalyst is 0.01-0.1% of the mass of the dibasic acid; the mass ratio of the coupling agent-modified titanium dioxide to the polyester oligomer is 5-8:1; The coupling agent is γ-aminopropyltriethoxysilane or γ-aminopropyltrimethoxysilane; the mass of the coupling agent is 3-5% of the mass of titanium dioxide; the organic modification is completed in a high-speed blender at a speed of 2500-3000 r / min, a temperature of 80-100°C, and a time of 2-3 hours; The spinning adopts a hollow special-shaped spinneret; the coated modified titanium dioxide is respectively gathered and exposed on the inner surface and the outer surface of the hollow fiber, thereby forming a large number of convex structures on the inner surface and the outer surface of the fiber.

2. The method for preparing a raw yarn sunscreen clothing fabric according to claim 1, characterized in that: The thickness of polyester oligomers on the titanium dioxide surface is 10~100nm.

3. The method for preparing a raw yarn sunscreen clothing fabric according to claim 1, characterized in that: The preparation process of the spinning melt is as follows: first, resin A is melt-blended with coated modified titanium dioxide to obtain a masterbatch with a concentration of 50-65wt%, and then the masterbatch is melt-blended with resin B through a single-screw extruder to obtain a spinning melt, wherein resin A and resin B are the same substance, the aspect ratio of the screw is 25-30:1, and the temperature of zones 1 to 5 of the single-screw extruder is 240-280°C.

4. The method for preparing a raw yarn sunscreen clothing fabric according to claim 1, characterized in that: The production process of sunscreen fiber is as follows: spinning melt is extruded from a hollow special-shaped spinneret → primary cooling → primary winding → secondary cooling → oiling → drafting → false deformation → heat setting → secondary winding; The cold air temperature used for primary cooling is 15~25℃; the speed of primary winding is 800~1200m / min; secondary cooling refers to storage for 24h at a temperature of 20~30℃ and a relative humidity of 60~70%; the oil concentration used for oiling is 10~18wt%, and the oil tanker speed is 4~6 rpm; the drawing speed is 780~850m / min, and the drawing temperature is 80~120℃; false twist deformation is carried out on a texturing machine, with a speed ratio of 1.5~1.7, the temperature of the first hot box is 150~180℃, and the temperature of the second hot box is 120~130℃; the heat setting temperature is 135~145℃; the speed of secondary winding is 4500~4600m / min.

5. The method for preparing a raw yarn sunscreen clothing fabric according to claim 1, characterized in that: The specifications of sunscreen fiber are 20~50D / 12~36F; the specifications of sunscreen yarn are 20~50 deniers; the original yarn sunscreen clothing fabric is knitted fabric, the number of circular knitting machines is 40G, and the weight is 150~300g / m 2 Or, the raw yarn sunscreen clothing fabric is a woven plain fabric with a warp density of 120-130 strands / 10cm, a weft density of 130-150 strands / 10cm, and a gram weight of 40-300g / m 2 Or, the raw yarn sunscreen clothing fabric is a woven twill fabric with a warp density of 120-190 strands / 10cm, a weft density of 140-150 strands / 10cm, and a gram weight of 60-300g / m 2 The UPF value of the original yarn sun protection clothing fabric is 50~1300. The UPF value change rate after washing 30 times is no more than 5%. The water droplet diffusion time is 1~2s, the water absorption rate is 105~120%, the maximum diffusion radius is 25~30mm, the diffusion speed is >4mm / s, and the 100% water content tensile force increase rate does not exceed 20%.

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