Waterproof coating of textile fabric and preparation method

Abstract

The invention belongs to the technical field of textiles, and discloses a waterproof coating of a textile fabric and a preparation method thereof.The preparation method includes the steps that S11, anhydrous tetrahydrofuran is added into a drying container to serve as a main solvent; s12, adding deionized water and an acid catalyst into the main solvent, and stirring and mixing; s13, dropwise adding tetraethoxysilane into a mixed system in the step S12 under a stirring condition, and continuously stirring at room temperature; s14, fluorine-containing alkoxy silane is dropwise added into a system in the step S13, and after dropwise adding is completed, sealing stirring is conducted at the room temperature, so that a super-hydrophobic membrane layer solution is obtained. The preparation method has the beneficial effects that the contradiction between easy dirt blockage and air permeability attenuation of a functional membrane is solved, and the problem that the air permeability of a microporous membrane is irreversibly reduced due to the fact that pores are easily blocked by grease and dirt is solved.

Description

Technical Field

[0001] This invention relates to the field of textile technology, and in particular to a waterproof coating for textiles and its preparation method. Background Technology

[0002] Waterproof and breathable fabrics are widely used in outdoor clothing, protective equipment, and other fields. Their core technology lies in their ability to block liquid water penetration while allowing water vapor (sweat) to escape, thus keeping the user dry and comfortable. The closest existing technology typically employs a multi-layered composite structure to achieve this function, with the most common structure being a three-layer design: Outer layer (fabric layer): Usually a durable textile woven from nylon or polyester fibers, providing basic mechanical strength and abrasion resistance. This outer fabric is usually treated with a durable water-repellent (DWR) treatment, making its surface hydrophobic, causing water droplets to form and roll off, thereby reducing surface wetting and moisture load. Middle layer (functional membrane / coating layer): This is the core layer that achieves the waterproof and breathable function. Mainstream technologies fall into two categories: Microporous membranes (such as ePTFE membranes): These use physical methods to create micropores with a pore size much smaller than the diameter of a water droplet (approximately 100 micrometers) but larger than the diameter of a water vapor molecule (approximately 0.0004 micrometers), allowing gas to pass through while blocking liquid water. Non-porous hydrophilic membranes (such as TPU / PU membranes): These rely on the hydrophilic groups on the polymer chains to adsorb, transfer, and desorb water vapor molecules, achieving unidirectional moisture conduction. Inner layer (protective layer / lining): This is usually a thin layer of knitted or non-woven fabric used to protect the functional membrane of the intermediate layer from abrasion, scaling, or direct contact with the skin.

[0003] Existing technologies employ a basic three-layer composite structure: an outer layer, a functional layer, and an inner layer. The outer layer uses conventional nylon or polyester textile fabric and undergoes DWR treatment. This is a common practice in existing technologies to achieve a preliminary water-repellent effect. A functional membrane (whether microporous or hydrophilic) is used as the key waterproof and breathable medium, with an inner lining layer to protect it. However, this structure is highly dependent on temperature and humidity; its moisture permeability is significantly affected by ambient temperature and humidity. In low-temperature, dry environments, the absorption and conduction of moisture by the hydrophilic groups are insufficient, resulting in poor moisture permeability. To achieve sufficient waterproofness, a thicker coating is often required, leading to a stiff fabric feel, a plastic-like texture, and high friction noise. Traditional PU coatings may also involve environmentally unfriendly solvents during production.

[0004] Therefore, it is necessary to provide a waterproof coating for textiles and a preparation method to resolve the contradiction between the easy clogging of functional membranes and the reduction of breathability, and to address the problem that the breathability of microporous membranes is irreversibly reduced due to the easy clogging of pores by grease and dirt. Summary of the Invention

[0005] This invention discloses a waterproof coating for textiles and its preparation method, which can be directly applied to the textile industry. It is suitable for surface processing of textile materials such as shoe uppers, clothing, hats, umbrellas, and outdoor equipment. The equipment using this method belongs to the vacuum equipment industry and can effectively solve the technical problems involved in the background art.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] A waterproof coating for textiles comprises SiO2, Si-O-Si-(CH2)2(CF2)7CF3 and C2H5OH.

[0008] A method for preparing a waterproof coating on textiles includes two steps: solution preparation and solution spraying.

[0009] S1, Solution preparation;

[0010] S11. Add anhydrous tetrahydrofuran as the main solvent to a dry container;

[0011] S12. Add deionized water and acid catalyst to the main solvent and stir to mix;

[0012] S13. Under stirring conditions, tetraethyl orthosilicate is added dropwise to the mixture in step S12, and stirring is continued at room temperature.

[0013] S14. Add fluorinated alkoxysilane dropwise to the system of step S13. After the addition is complete, seal and stir at room temperature to obtain a superhydrophobic film solution.

[0014] S2. Solution spraying: Spray the superhydrophobic film solution obtained in step S14 onto the surface of the textile.

[0015] As a preferred improvement of the present invention: by volume ratio, 95-98 parts of anhydrous tetrahydrofuran, 0.04-0.06 parts of deionized water, 0.04-0.06 parts of acid catalyst, 1.8-2.2 parts of tetraethyl orthosilicate, and 1.4-1.6 parts of fluorinated alkoxysilane.

[0016] As a preferred improvement of the present invention: the acid catalyst is hydrochloric acid diluted with ethanol by mass, and the mass ratio of hydrochloric acid to ethanol is 1:8 to 1:12; the fluorinated alkoxysilane is heptadecafluorodecyltrimethoxysilane.

[0017] As a preferred improvement of the present invention, step S2 includes the following steps:

[0018] S21, Vacuuming;

[0019] S22, Plasma cleaning and activation;

[0020] S23, Vacuum spraying;

[0021] S24, plasma bombardment and heat curing.

[0022] As a preferred improvement of the present invention: step S21 specifically involves placing the textile into a plasma cleaning chamber and evacuating it to a vacuum of 0.1-10 Pa.

[0023] As a preferred improvement of the present invention: step S22 specifically involves, after the vacuum level is reached, introducing argon gas at 50-500 sccm, and after the vacuum stabilizes, turning on the plasma instrument for cleaning for 5-300 seconds.

[0024] As a preferred improvement of the present invention: Step S23 specifically involves, after cleaning, placing the textile into a movable spraying chamber and spraying the superhydrophobic film solution obtained in step S14, with the spraying flow rate set to 10-100 ml / min and the nozzle moving speed within the chamber being 1-200 mm / s.

[0025] As a preferred improvement of the present invention: Step S24 specifically involves placing the textile into a heat curing chamber after the spraying is completed. The chamber temperature is set to 30-80 degrees Celsius. After the temperature is reached, argon gas is introduced at 300 sccm. After the vacuum stabilizes, plasma curing is performed. After curing is completed, heating is stopped, the vacuum is broken for 1-2 seconds, and then the gas is evacuated to 1-10 Pa. This process is repeated to quickly cool down to 40 degrees Celsius and completely break the vacuum. The product is then manufactured.

[0026] The beneficial effects of this invention are as follows:

[0027] To resolve the contradiction between the easy clogging of functional membranes and the decline in breathability, and addressing the problem of irreversible decrease in breathability caused by the pores of microporous membranes being easily clogged by grease and dirt, a functional layer structure with anti-fouling, self-cleaning, or easy-to-clean properties is provided to maintain its long-term, stable high breathability. Furthermore, to optimize the wearing experience and fabric performance, and addressing the common problems of existing laminated fabrics such as stiffness, high friction noise, and a sharp drop in breathability under high temperature and humidity static environments, material and structural innovations are used to provide a softer, quieter fabric with more stable and balanced breathability under different environmental conditions. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0029] Figure 1 This is a schematic diagram of the waterproof coating spraying process for textiles according to the present invention;

[0030] Figure 2 This is a schematic diagram of the structure of the present invention;

[0031] Figure 3 This is a schematic diagram illustrating the effect of the product of the present invention. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0033] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0034] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0035] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0036] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0037] A method for preparing a superhydrophobic film solution includes the following steps: S1. Adding anhydrous tetrahydrofuran as the main solvent in a dry container; S2. Adding deionized water and an acid catalyst to the main solvent and stirring to mix; S3. Under stirring conditions, adding tetraethyl orthosilicate dropwise to the mixture in step S2 and continuously stirring at room temperature to carry out a preliminary hydrolysis reaction; S4. Adding a fluoroalkoxysilane dropwise to the reaction system in step S3, and after the addition is complete, sealing and stirring at room temperature to carry out a condensation reaction to obtain the superhydrophobic film solution.

[0038] In this embodiment, the acid catalyst is hydrochloric acid diluted with ethanol by mass, and the mass ratio of hydrochloric acid to ethanol is 1:8 to 1:12. The fluorinated alkoxysilane is heptadecafluorodecyltrimethoxysilane. The volume ratio of each raw material component is as follows: 95-98 parts anhydrous tetrahydrofuran, 0.04-0.06 parts deionized water, 0.04-0.06 parts the acid catalyst, 1.8-2.2 parts tetraethyl orthosilicate, and 1.4-1.6 parts the fluorinated alkoxysilane.

[0039] The film preparation process involves pre-vacuuming, plasma bombardment, vacuum spraying, and plasma bombardment / heat curing, ensuring the necessary conditions for producing a product that meets quality standards. These conditions include: vacuum conditions of 0.1~10 Pa during preparation; argon gas flow rate of 50~500 sccm for plasma cleaning; power of the AECESAR1310E RF power supply of 200~1000 W; cleaning time of 5~300 s; solution spraying flow rate of 10~100 ml / min; spraying speed of 0~200 mm / s; curing temperature of 30~80 degrees Celsius; power of the TruPlasmaDC3020 bipolar pulse power supply of 500~5000 W; and argon gas flow rate of 50~1000 sccm for plasma curing.

[0040] Example 1

[0041] The plan requires the use of vacuum spraying equipment and solution preparation.

[0042] Solution preparation:

[0043] Add 96.4 parts of anhydrous tetrahydrofuran to a dry beaker as the main solvent; then add 0.05 parts of deionized water and 0.05 parts of concentrated hydrochloric acid diluted with 10 times the mass of ethanol as a catalyst, and stir; during the stirring process, slowly add 2 parts of tetraethyl orthosilicate as a network forming agent, and continue stirring at room temperature for 30 minutes to allow it to undergo preliminary hydrolysis.

[0044] Hydrolysis reaction equation: Si(OC2H5)4 + 4H2O → Si(OH)4 + 4C2H5OH.

[0045] After 30 minutes, slowly add 1.5 parts of heptadecafluorodecyltrimethoxysilane as the main active film-forming substance. After the addition is complete, seal and stir at room temperature for 24 hours. Then, place in a 40°C water bath to continue the reaction for 2 hours to promote condensation.

[0046] Covalent bond condensation: Si-OH + HO-Si → Si-O-Si + H2O (water condensation).

[0047] Si-OH+E t O-Si→Si-O-Si+C2H5OH (alcohol condensation).

[0048] The solution is now prepared and stored in a sealed glass bottle.

[0049] Therefore, the main components in the resulting solution are SiO2, Si-O-Si-(CH2)2(CF2)7CF3 and C2H5OH.

[0050] Film application process using spray coating equipment:

[0051] The entire preparation process is carried out in a continuous vacuum spraying equipment (three interconnected vacuum chambers with openable and closable valves at the connection between the chambers, and motor pulleys inside the chambers for material transfer). The raw material, polyester fiber fabric, is fed into the vacuum chamber, and the surface of the raw material is plasma cleaned using an AE CESAR 1310E radio frequency power supply. Then, it enters the spraying chamber and is evenly sprayed onto the surface of the raw material. In the curing chamber, plasma curing is performed at a temperature of 80 degrees Celsius using a TruPlasma DC 3020 bipolar pulse power supply. Finally, the vacuum is broken by cooling and the finished product is removed.

[0052] Significantly enhanced antifouling and easy-to-clean properties: The surface of the composite functional membrane layer is coated with a perfluoroalkyl ether-modified silica nanocoating. This coating imparts superhydrophobic (contact angle >150°) and superoleophobic properties to the membrane surface, while its micro-nano structure makes it difficult for pollutants to adhere firmly. Everyday stains (such as oil stains and sweat stains) are more easily removed by washing or simple wiping, fundamentally alleviating the core defect of microporous membranes being easily clogged, leading to a permanent decrease in breathability.

[0053] Significantly improved overall durability and comfort of the fabric: By integrating the functional membrane into a single, controllable layer, not only are the tear and puncture resistance of the membrane improved, but the fabric also gains excellent elastic recovery. The resulting fabric is soft, elastic, and produces low friction noise, providing a wearing experience close to that of ordinary knitted fabrics. It overcomes the stiffness and rigidity of traditional laminated fabrics while ensuring its reliability and durability under complex activities.

[0054] Working principle:

[0055] Preparation of 100ml solution:

[0056] Add 96.4 ml of anhydrous tetrahydrofuran to a dry beaker as the main solvent; then add 0.05 ml of deionized water and 0.05 ml of concentrated hydrochloric acid diluted with 10 times its mass of ethanol as a catalyst, and stir. During stirring, slowly add 2 ml of tetraethyl orthosilicate as a network forming agent, and continue stirring at room temperature for 30 minutes to allow for initial hydrolysis. After 30 minutes, slowly add 1.5 ml of heptadecafluorodecyltrimethoxysilane as the main active film-forming substance. After the addition is complete, seal and stir at room temperature for 24 hours. Then, place the mixture in a 40°C water bath and continue the reaction for 2 hours to promote condensation. The solution is now ready and should be stored in a sealed glass bottle.

[0057] 1. Feeding and Vacuuming. After the equipment is ready for operation, place the raw material into the carrier tray, and the carrier tray enters chamber 1 (plasma cleaning chamber). Vacuum is then drawn to a range of 0.1~1 Pa.

[0058] 2. Plasma cleaning. After the vacuum level is reached, argon gas at 50~500 sccm is introduced. After the vacuum stabilizes, the RF power supply AE CESAR 1310E is turned on and the power is set to 200~1000W. The cleaning time is about 60 seconds.

[0059] 3. Solution spraying. After cleaning, the carrier tray enters chamber 2 (movable spraying chamber). The spraying flow rate is set to 10~100ml / min, the nozzle moving speed in the chamber is 0~200mm / s (0 is taken as fixed point spraying), and the spraying time is about 80s.

[0060] 4. Film curing. After spraying, the carrier disk enters cavity 3 (thermal curing cavity). The cavity temperature is set to about 80 degrees Celsius. After the temperature is reached, argon gas is introduced at 50~1000 sccm. After the vacuum stabilizes, a bipolar pulse power supply is used for plasma curing. The power supply power is set to 500~5000w, and the curing time is about 60s.

[0061] 5. Cooling and unloading. After curing, stop heating, break the vacuum for 1-2 seconds, then evacuate to 1-10 Pa. Repeat this process to quickly cool down to about 40 degrees Celsius, then completely break the vacuum, unload the material from the tray, and the product is finished.

[0062] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. Other modifications can be easily made by those skilled in the art. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A water repellent coating for a textile fabric, characterised in that: SiO2, Si-O-Si-(CH2)2(CF2)7CF3 and C2H5OH.

2. A process for the preparation of a water repellent coating for a textile fabric as claimed in claim 1, characterized in that: The method comprises two steps of solution preparation and solution spraying. S1, solution preparation; S11, adding anhydrous tetrahydrofuran as a main solvent in a dry container; S12, adding deionized water and an acid catalyst into the main solvent, and stirring and mixing; S13, under stirring, adding tetraethyl orthosilicate into the mixed system of step S12, and continuously stirring at room temperature; S14, adding fluorine-containing alkoxy silane into the system of step S13 dropwise, and after the addition is completed, stirring at room temperature in a sealed state to obtain a super-hydrophobic film layer solution; S2, solution spraying, spraying the super-hydrophobic film layer solution obtained in step S14 onto the surface of the textile.

3. A water repellent coating for a textile fabric according to claim 2, characterised in that: The anhydrous tetrahydrofuran, the deionized water, the acid catalyst, the tetraethyl orthosilicate and the fluorine-containing alkoxy silane are mixed in a volume ratio of 95-98:0.04-0.06:0.04-0.06:1.8-2.2:1.4-1.

6.

4. A method of making a water repellent coating for a textile according to claim 2, characterized in that: The acid catalyst is hydrochloric acid diluted with ethanol, and the dilution mass ratio of the hydrochloric acid to the ethanol is 1:8 to 1:12; and the fluorine-containing alkoxy silane is heptadecafluorodecyltrimethoxysilane.

5. A method of making a water repellent coating for a textile according to claim 2, characterized in that: The step S2 comprises the following steps: S21, vacuumizing; S22, plasma cleaning and activation; S23, vacuum spraying; S24, plasma bombardment and heating curing.

6. A method of making a water repellent coating for a textile according to claim 5, characterized in that: In the step S21, the textile is placed into a plasma cleaning cavity, and vacuumized to 0.1-10 Pa.

7. A method of making a water repellent coating for a textile according to claim 5, characterized in that: In the step S22, after the vacuum degree reaches, 50-500 sccm of argon is introduced, and after the vacuum is stabilized, the plasma instrument is started to clean for 5-300 S.

8. A method of making a water repellent coating for a textile according to claim 5, characterized in that: In the step S23, after the cleaning is completed, the textile is placed into a movable spraying cavity, the super-hydrophobic film layer solution obtained in step S14 is sprayed, the spraying flow rate is set to 10-100 ml / min, and the moving speed of the nozzle in the cavity is 1-200 mm / s.

9. A method of making a water repellent coating for a textile according to claim 5, characterized in that: In the step S24, after the spraying is completed, the textile is placed into a heat curing treatment cavity, the cavity temperature is set to 30-80 degrees, after the temperature reaches, 300 sccm of argon is introduced, the vacuum is stabilized, and then the plasma curing is performed, after the curing is completed, the heating is stopped, the vacuum is destroyed for 1-2 s, the air is pumped to 1-10 Pa, the temperature is rapidly reduced to 40 degrees after the repeated operation, the vacuum is completely destroyed, and the product is completed.

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