Preparation method of fluorine-free waterproof fabric

Abstract

The application belongs to the technical field of fabric, and particularly relates to a preparation method of fluorine-free waterproof fabric, which is subjected to coupling reaction after being steamed and dried to form a hydrophobic transition film layer, and deposition and hydrolytic condensation of methyltrimethoxysilane and ethyltriethoxysilane are utilized to form a methyl-ethyl composite hydrophobic layer. The application solves the defects of the existing fluorine-free waterproof fabric, forms a silicon-oxygen transition layer by utilizing a silane coupling agent and ethyl silicate, forms a silicon-based waterproof finishing liquid by utilizing methyltrimethoxysilane, ethyltriethoxysilane and ethyl silicate, and forms an integrated silicon-oxygen hydrophobic layer.

Description

Technical Field

[0001] This invention belongs to the field of fabric technology, specifically relating to a method for preparing a fluorine-free waterproof fabric. Background Technology

[0002] Fluorine-free waterproof fabrics refer to functional fabrics that achieve water repellency through a fluorine-free waterproof finishing process without the addition of perfluorinated / polyfluorinated compounds. They meet current environmental protection requirements and are the mainstream alternative to traditional fluorinated waterproof fabrics. These fluorine-free waterproof fabrics are environmentally friendly, non-irritating to the human body, and suitable for daily commutes and general outdoor activities. They are widely used in outdoor jackets, children's wear, underwear, and home textiles. However, the abrasion resistance and washability of fluorine-free waterproof fabrics are significantly weaker than those of fluorinated fabrics. Their waterproof effect cannot be maintained long-term and can only meet daily needs. In harsh environments such as continuous water flow impact and repeated membrane application, the waterproof performance of fluorine-free waterproof fabrics deteriorates significantly and is far inferior to that of fluorinated fabrics. Summary of the Invention

[0003] To address the problems in the prior art, this invention provides a method for preparing a fluorine-free waterproof fabric, which solves the defects of existing fluorine-free waterproof fabrics. It utilizes a silane coupling agent and ethyl silicate to form a silicon-oxygen transition layer, and utilizes methyltrimethoxysilane, ethyltriethoxysilane and ethyl silicate to form a silicon-based waterproof finishing liquid, thereby forming an integrated silicon-oxygen hydrophobic layer.

[0004] To achieve the above technical objectives, the technical solution of the present invention is as follows: A method for preparing a fluorine-free waterproof fabric includes the following steps: Step 1: The fabric that has been refined, dyed, washed and dried is placed in water for steaming and then dried to obtain clean fabric. The steaming temperature is 95-100℃ and the drying temperature is 100-110℃. This step uses steaming to accelerate the flow of water, thereby peeling off and removing impurities from the surface of the fabric. The drying process removes moisture from the surface of the fabric, resulting in a fabric with completely removed surface impurities. Step 2: Add the silane coupling agent and ethyl silicate to an ethanol-water solution and stir until homogeneous to obtain a silicon-based immersion solution. Then, immerse the fabric in the solution at room temperature for 20-30 minutes, remove and dry to obtain a transition-coated fabric. The mass ratio of the silane coupling agent to ethyl silicate is 1:0.4-0.7, and the silane coupling agent used is KH550 or KH560. The volume ratio of ethanol to water in the ethanol-water solution is 9:1, and the mass fraction of the silane coupling agent in the ethanol-water solution is 1-3%. The stirring speed for homogeneous mixing is 200-400 r / min, and the mass ratio of the fabric to the silicon-based immersion solution is 1:10-1. 2. The drying temperature is 105-110℃, and the time is 2-3 minutes. This step utilizes the solubility of silane coupling agent and ethyl silicate in ethanol to form a homogeneous dispersion. A small amount of water is homogeneously dispersed in ethanol, which can hydrolyze the silane coupling agent and ethyl silicate in situ to form hydroxyl structures. The presence of ethanol also reduces premature condensation between silanol molecules, maintaining the solution's active window. The clean fabric is then immersed in the solution to form a soaking. The permeability and film-forming properties of ethanol ensure that the hydrolysate of silane coupling agent and ethyl silicate is coated on the surface of the fabric fibers, forming a fully encapsulated structure, thereby forming a transition layer of the silicon-oxygen system. Step 3: Methyltrimethoxysilane, ethyltriethoxysilane, and ethyl silicate are placed in ethanol and stirred until homogeneous. Then, water is slowly added and stirred to obtain a silicon-based waterproof finishing solution. The mass ratio of methyltrimethoxysilane, ethyltriethoxysilane, and ethyl silicate is 1:1-1.2:0.2-0.4. The mass fraction of methyltrimethoxysilane in ethanol is 2-5%. The stirring speed is 200-400 r / min. The mass ratio of water to ethanol is 1:15-20. The water addition rate is 1-3 mL / min, and the stirring speed is 500-800 r / min. This step utilizes the excellent solubility of ethanol to form a homogeneous dispersion of methyltrimethoxysilane, ethyltriethoxysilane, and ethyl silicate, obtaining a mixture of various silicon-based precursors. The addition of a small amount of water ensures the in-situ hydrolysis of methyltrimethoxysilane, ethyltriethoxysilane, and ethyl silicate, while ethanol can prevent the condensation of silanols. Step 4: Place the transition-coated fabric into a silicone-based waterproof finishing solution and stir for 20-30 minutes. Let it stand for 10-20 minutes, then remove it and pre-bake for 2-5 minutes, followed by baking for 5-10 minutes. After natural cooling, a fluorine-free waterproof fabric is obtained. The ratio of the transition-coated fabric to the silicone-based waterproof finishing solution is 1:8-10. The stirring speed is 200-500 r / min, the standing temperature is room temperature, the pre-baking temperature is 100-120℃, and the baking temperature is 180-190℃. This step uses low-speed stirring to ensure that the fabric is completely wetted, that is, the silicone-based waterproof finishing solution completely penetrates the surface of the fabric monofilament, thereby forming a surface liquid film. Through standing, the hydrolysates of methyltrimethoxysilane, ethyltriethoxysilane, and ethyl silicate are oriented, ensuring that the methyl and ethyl groups face outwards. The pre-baking and baking treatments ensure that the silanol groups form condensation polymerization and form a stable connection through the transition layer, thereby ensuring that it is stably connected to the fabric.

[0005] The fluorine-free waterproof fabric prepared by the above method has a layer of directional hydrophobic layer with alternating methyl and ethyl groups on its surface.

[0006] As can be seen from the above description, the present invention has the following advantages: 1. This invention solves the defects of existing fluorine-free waterproof fabrics by using silane coupling agent and ethyl silicate to form a silicon-oxygen transition layer, and using methyltrimethoxysilane, ethyltriethoxysilane and ethyl silicate to form a silicon-based waterproof finishing liquid, thus forming an integrated silicon-oxygen hydrophobic layer. 2. This invention utilizes methyltrimethoxysilane, ethyltriethoxysilane and ethyl silicate as waterproof precursors, which are hydrolyzed to form siloxane active materials containing silanol groups. The materials are then allowed to stand to form an oriented arrangement, ensuring that the methyl and ethyl groups are alternately facing outwards. 3. The transition layer of the present invention uses silane coupling agent and ethyl silicate as precursors to form a dense silicon-oxygen transition layer. Methyltrimethoxysilane, ethyltriethoxysilane and ethyl silicate form a silicon-oxygen waterproof layer. Both the silicon-oxygen waterproof layer and the dense silicon-oxygen transition layer are silicon-oxygen systems, which can form a silicon-oxygen structural connection to ensure the fixation of the waterproof layer on the fabric surface. Detailed Implementation

[0007] The present invention will be described in detail with reference to the embodiments, but the claims of the present invention are not intended to limit the scope of the invention. Example 1

[0008] A method for preparing a fluorine-free waterproof fabric includes the following steps: Step 1: The fabric that has been refined, dyed, washed and dried is placed in water and steamed, and then removed and dried to obtain clean fabric; the steaming temperature is 95℃ and the drying temperature is 100℃. Step 2: Add silane coupling agent and ethyl silicate to an ethanol-water solution and stir until homogeneous to obtain a silicon-based soaking solution. Then, immerse the fabric in the solution and soak it at room temperature for 20 minutes. After removal, dry the fabric to obtain a transition-coated fabric. The mass ratio of silane coupling agent to ethyl silicate is 1:0.7, and the silane coupling agent used is KH550. The volume ratio of ethanol to water in the ethanol-water solution is 9:1. The mass fraction of silane coupling agent in the ethanol-water solution is 3%. The stirring speed for homogeneous mixing is 200 r / min. The mass ratio of fabric to silicon-based soaking solution is 1:12. The drying temperature is 105℃ and the drying time is 2 minutes. Step 3: Methyltrimethoxysilane, ethyltriethoxysilane, and ethyl silicate are placed in ethanol and stirred until homogeneous. Then, water is slowly added and stirred to obtain a silicone-based waterproof finishing solution. The mass ratio of methyltrimethoxysilane, ethyltriethoxysilane, and ethyl silicate is 1:1.2:0.4. The mass fraction of methyltrimethoxysilane in ethanol is 5%. The stirring speed for homogeneous mixing is 200 r / min. The mass ratio of water to ethanol is 1:15. The water addition rate is 1 mL / min, and the stirring speed is 500 r / min. Step 4: Place the transition coating fabric into the silicone-based waterproof finishing solution and stir for 20 minutes, let it stand for 10 minutes, take it out and pre-bake for 2 minutes, then bake for 5 minutes, and cool naturally to obtain the fluorine-free waterproof fabric; the ratio of the transition coating fabric to the silicone-based waterproof finishing solution is 1:10, the stirring speed is 200 r / min, the standing temperature is room temperature, the pre-bake temperature is 100℃, and the baking temperature is 180℃. Example 2

[0009] A method for preparing a fluorine-free waterproof fabric includes the following steps: Step 1: The fabric that has been refined, dyed, washed and dried is placed in water and steamed, then removed and dried to obtain clean fabric; the steaming temperature is 100℃ and the drying temperature is 110℃. Step 2: Add silane coupling agent and ethyl silicate to an ethanol-water solution and stir until homogeneous to obtain a silicon-based soaking solution. Then, immerse the fabric in the solution and soak it at room temperature for 30 minutes. After removal, dry the fabric to obtain a transition-coated fabric. The mass ratio of silane coupling agent to ethyl silicate is 1:0.4, and the silane coupling agent used is KH560. The volume ratio of ethanol to water in the ethanol-water solution is 9:1. The mass fraction of silane coupling agent in the ethanol-water solution is 1%. The stirring speed for homogeneous mixing is 400 r / min. The mass ratio of fabric to silicon-based soaking solution is 1:10. The drying temperature is 110℃ and the drying time is 3 minutes. Step 3: Methyltrimethoxysilane, ethyltriethoxysilane, and ethyl silicate are placed in ethanol and stirred until homogeneous. Then, water is slowly added and stirred to obtain a silicone-based waterproof finishing solution. The mass ratio of methyltrimethoxysilane, ethyltriethoxysilane, and ethyl silicate is 1:1:0.2. The mass fraction of methyltrimethoxysilane in ethanol is 2%. The stirring speed for homogeneous mixing is 400 r / min. The mass ratio of water to ethanol is 1:20. The water addition rate is 3 mL / min, and the stirring speed is 800 r / min. Step 4: Place the transition coating fabric into the silicone-based waterproof finishing solution and stir for 20-30 minutes, let it stand for 20 minutes, take it out and pre-bake for 5 minutes, then bake for 10 minutes, and cool naturally to obtain the fluorine-free waterproof fabric; the ratio of the transition coating fabric to the silicone-based waterproof finishing solution is 1:8, the stirring speed is 500 r / min, the standing temperature is room temperature, the pre-bake temperature is 120℃, and the baking temperature is 190℃. Example 3

[0010] A method for preparing a fluorine-free waterproof fabric includes the following steps: Step 1: The fabric that has been refined, dyed, washed and dried is placed in water and steamed, and then removed and dried to obtain clean fabric; the steaming temperature is 100℃ and the drying temperature is 105℃. Step 2: Add silane coupling agent and ethyl silicate to an ethanol-water solution and stir until homogeneous to obtain a silicon-based soaking solution. Then, immerse the fabric in the solution at room temperature for 25 minutes, remove it, and dry it to obtain a transition-coated fabric. The mass ratio of silane coupling agent to ethyl silicate is 1:0.6, and the silane coupling agent used is KH550. The volume ratio of ethanol to water in the ethanol-water solution is 9:1, the mass fraction of silane coupling agent in the ethanol-water solution is 2%, the stirring speed for homogeneous mixing is 300 r / min, the mass ratio of fabric to silicon-based soaking solution is 1:11, and the drying temperature is 110℃ for 3 minutes. Step 3: Methyltrimethoxysilane, ethyltriethoxysilane, and ethyl silicate are placed in ethanol and stirred until homogeneous. Then, water is slowly added and stirred to obtain a silicone-based waterproof finishing solution. The mass ratio of methyltrimethoxysilane, ethyltriethoxysilane, and ethyl silicate is 1:1.1:0.3. The mass fraction of methyltrimethoxysilane in ethanol is 4%. The stirring speed for homogeneous mixing is 300 r / min. The mass ratio of water to ethanol is 1:18. The water addition rate is 2 mL / min, and the stirring speed is 700 r / min. Step 4: Place the transition coating fabric into the silicone-based waterproof finishing solution and stir for 25 minutes, let it stand for 15 minutes, take it out and pre-bake for 4 minutes, then bake for 8 minutes, and cool naturally to obtain the fluorine-free waterproof fabric; the ratio of the transition coating fabric to the silicone-based waterproof finishing solution is 1:9, the stirring speed is 400 r / min, the standing temperature is room temperature, the pre-bake temperature is 110℃, and the baking temperature is 185℃.

[0011] Comparative Example 1 A method for preparing a fluorine-free waterproof fabric includes the following steps: Step 1: The fabric that has been refined, dyed, washed and dried is placed in water and steamed, and then removed and dried to obtain clean fabric; the steaming temperature is 100℃ and the drying temperature is 105℃. Step 2: Add silane coupling agent and ethyl silicate to an ethanol-water solution and stir until homogeneous to obtain a silicon-based soaking solution. Then, immerse the fabric in the solution at room temperature for 25 minutes, remove it, and dry it to obtain a transition-coated fabric. The mass ratio of silane coupling agent to ethyl silicate is 1:0.6, and the silane coupling agent used is KH550. The volume ratio of ethanol to water in the ethanol-water solution is 9:1, the mass fraction of silane coupling agent in the ethanol-water solution is 2%, the stirring speed for homogeneous mixing is 300 r / min, the mass ratio of fabric to silicon-based soaking solution is 1:11, and the drying temperature is 110℃ for 3 minutes. Step 3: Add ethyl silicate to ethanol and stir until homogeneous. Then slowly add water and stir to obtain a silicone-based waterproof finishing solution. The mass fraction of ethyl silicate in ethanol is 1.2%. The stirring speed for homogeneous mixing is 300 r / min. The mass ratio of water to ethanol is 1:18. The water addition rate is 2 mL / min. The stirring speed is 700 r / min. Step 4: Place the transition coating fabric into the silicone-based waterproof finishing solution and stir for 25 minutes, let it stand for 15 minutes, take it out and pre-bake for 4 minutes, then bake for 8 minutes, and cool naturally to obtain the fluorine-free waterproof fabric; the ratio of the transition coating fabric to the silicone-based waterproof finishing solution is 1:9, the stirring speed is 400 r / min, the standing temperature is room temperature, the pre-bake temperature is 110℃, and the baking temperature is 185℃.

[0012] Comparative Example 2 A method for preparing a fluorine-free waterproof fabric includes the following steps: Step 1: The fabric that has been refined, dyed, washed and dried is placed in water and steamed, and then removed and dried to obtain clean fabric; the steaming temperature is 100℃ and the drying temperature is 105℃. Step 2: Methyltrimethoxysilane, ethyltriethoxysilane, and ethyl silicate are placed in ethanol and stirred until homogeneous. Then, water is slowly added and stirred to obtain a silicone-based waterproof finishing solution. The mass ratio of methyltrimethoxysilane, ethyltriethoxysilane, and ethyl silicate is 1:1.1:0.3. The mass fraction of methyltrimethoxysilane in ethanol is 4%. The stirring speed for homogeneous mixing is 300 r / min. The mass ratio of water to ethanol is 1:18. The water addition rate is 2 mL / min, and the stirring speed is 700 r / min. Step 3: Place the clean fabric into the silicone-based waterproof finishing solution and stir for 25 minutes, let it stand for 15 minutes, take it out and pre-bake for 4 minutes, then bake for 8 minutes, and cool naturally to obtain the fluorine-free waterproof fabric; the ratio of the transition coating fabric to the silicone-based waterproof finishing solution is 1:9, the stirring speed is 400 r / min, the standing temperature is room temperature, the pre-bake temperature is 110℃, and the baking temperature is 185℃.

[0013] Comparative Example 3 A method for preparing a fluorine-free waterproof fabric involves using a conventional method with an organosilicon waterproofing agent as the waterproofing finishing liquid. The fabric, which has been refined, dyed, washed, and dried, is then subjected to padding treatment, removed, and baked to obtain the fluorine-free waterproof fabric. The organosilicon waterproofing agent used is ECO water shield from Suzhou Xinke Chemical Co., Ltd.

[0014] Performance testing The fluorine-free waterproof fabrics prepared in Examples 1-3 and Comparative Examples 1-3 were used as test samples for performance testing, and the results are as follows: 1. Dynamic waterproof performance (spray method): Refer to GB / T4745-2012, tilt the fabric at 45° and spray it with water at a specified flow rate. Score the fabric surface water-covered area and penetration (1-5 levels, with 5 being the best).

[0015] 2. Water resistance durability after washing: Perform 30 standard water washes (simulating daily use) according to GB / T8629-2017 "Test Procedures for Household Washing and Drying of Textiles", and retest the dynamic water resistance performance after washing.

[0016] 3. Friction resistance (dry / wet friction): The fabric surface is rubbed with a friction cloth (dry / wet) under a specified pressure, and then the dynamic waterproof performance is retested.

[0017] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Spraying level 5 5 5 1 5 4 Spraying level after water washing 5 5 5 0 5 3 Spraying level after dry friction 5 5 5 0 4 3 Spray level after wet friction 5 5 5 1 4 3 Note: The above raw materials are mainly silane materials and no fluorine-containing substances are used. Therefore, no fluorine content testing was conducted. That is, starting from the source of raw materials, the intake of fluorine is effectively prevented, and there is no fluorine content problem.

[0018] The above comparison shows that this technical solution utilizes methyltrimethoxysilane, ethyltriethoxysilane, and ethyl silicate to form a methyl-ethyl interlaced hydrophobic layer on the surface of the fabric monofilament, and connects it to the fabric with a dense silicon-oxygen structure as a transition layer, maintaining good stability during repeated washing, dry friction, and wet friction. The comparison between Comparative Examples 2-3 and Example 3 shows that the fluorine-free waterproof fabric prepared by this technical solution forms a stable silicon-oxygen structure under the action of silane coupling agent and ethyl silicate, ensuring the stability of its hydrophobic layer during friction and washing. In Comparative Example 1, the ethyl silicate, after hydrolysis and condensation, yields silica, which is hydrophilic and cannot achieve a waterproof effect.

[0019] It is understood that the above detailed description of the present invention is for illustrative purposes only and is not intended to limit the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention to achieve the same technical effects; as long as the usage requirements are met, they are all within the protection scope of the present invention.

Claims

1. A method for preparing a fluorine-free waterproof fabric, characterized in that: Includes the following steps: Step 1: Put the fabric that has been refined, dyed, washed and dried into water and steam it. After taking it out and drying it, you will get a clean fabric. Step 2: Add silane coupling agent and ethyl silicate to an ethanol aqueous solution and stir until homogeneous to obtain a silicon-based immersion solution. Then, immerse the fabric in the solution at room temperature for 20-30 minutes, remove and dry to obtain a transition-coated fabric. Step 3: Add methyltrimethoxysilane, ethyltriethoxysilane and ethyl silicate to ethanol and stir until homogeneous. Then slowly add water and stir to obtain a silicone-based waterproof finishing solution. Step 4: Place the transition coating fabric into the silicone-based waterproof finishing solution and stir for 20-30 minutes. Let it stand for 10-20 minutes, then take it out and pre-bake for 2-5 minutes, then bake for 5-10 minutes. After natural cooling, you will get a fluorine-free waterproof fabric.

2. The method for preparing the fluorine-free waterproof fabric according to claim 1, characterized in that: The steaming temperature in step 1 is 95-100℃, and the drying temperature is 100-110℃.

3. The method for preparing the fluorine-free waterproof fabric according to claim 1, characterized in that: In step 2, the mass ratio of silane coupling agent to ethyl silicate is 1:0.4-0.7, and the silane coupling agent used is KH550 or KH560. The volume ratio of ethanol to water in the ethanol aqueous solution is 9:1, the mass fraction of the silane coupling agent in the ethanol aqueous solution is 1-3%, and the stirring speed for uniform stirring is 200-400 r / min.

4. The method for preparing the fluorine-free waterproof fabric according to claim 1, characterized in that: In step 2, the mass ratio of the fabric to the silicone soaking solution is 1:10-12, and the drying temperature is 105-110℃ for 2-3 minutes.

5. The method for preparing the fluorine-free waterproof fabric according to claim 1, characterized in that: In step 3, the mass ratio of methyltrimethoxysilane, ethyltriethoxysilane, and ethyl silicate is 1:1-1.2:0.2-0.4, the mass fraction of methyltrimethoxysilane in ethanol is 2-5%, and the stirring speed for uniform stirring is 200-400 r / min.

6. The method for preparing the fluorine-free waterproof fabric according to claim 1, characterized in that: In step 3, the mass ratio of water to ethanol is 1:15-20, the water addition rate is 1-3 mL / min, and the stirring speed is 500-800 r / min.

7. The method for preparing the fluorine-free waterproof fabric according to claim 1, characterized in that: In step 4, the ratio of the transition coating fabric to the silicone-based waterproof finishing liquid is 1:8-10, the stirring speed is 200-500 r / min, and the settling temperature is room temperature.

8. The method for preparing the fluorine-free waterproof fabric according to claim 1, characterized in that: The pre-baking temperature in step 4 is 100-120℃, and the baking temperature is 180-190℃.

9. The method for preparing the fluorine-free waterproof fabric according to claim 1, characterized in that: The fluorine-free waterproof fabric in step 4 has a layer of directional hydrophobic layer with alternating methyl and ethyl groups on its surface.