A self-roughening organosilicon superhydrophobic finishing agent, its preparation method and application

Abstract

The present invention provides a self-roughened organosilicon superhydrophobic finishing agent, a preparation method thereof and an application thereof, belonging to the technical field of textile finishing. In the present invention, vinyl silicone oil and a platinum catalyst are mixed to obtain a first component; vinyl silicone oil, hydrogen-containing silicone oil and an inhibitor are mixed to obtain a second component; the first and second components are mixed with a reinforcing agent, then dissolved in an organic solvent and water is added, and a finishing agent is obtained through dispersion. The method of the present invention utilizes the difference in solubility parameters of organosilicon polymers in organic solvents and water to cause supersaturation and precipitation, thereby forming a finishing agent; when the finishing agent is used for fabric finishing, heat curing treatment can be combined to promote rapid crosslinking before the complete diffusion of organosilicon droplets on the fabric surface, so as to realize the construction of a self-roughened surface. The finishing agent can endow the fabric with excellent hydrophobic effects and has good abrasion resistance, wash resistance and chemical stability, while having little influence on air permeability.

Description

Technical Field

[0001] The present invention relates to the technical field of textile finishing, and particularly to a self-roughened silicone superhydrophobic finishing agent, a preparation method thereof, and an application thereof. Background Art

[0002] With the progress of science and technology and the improvement of people's living standards, superhydrophobic textiles have received increasing attention. After being superhydrophobically finished, textiles not only have excellent superhydrophobic properties but also obtain higher added value. At present, they have been widely used in fields such as waterproof and antifouling, oil-water separation, self-cleaning, and smart fabrics. However, commonly used hydrophobic finishing agents on the market generally contain fluorine compounds. Although they can endow fabrics with good water repellency, their potential toxicity and bioaccumulation cannot be ignored. Therefore, exploring fluorine-free finishing technologies and developing fluorine-free waterproof products have become research hotspots in the direction of textile water repellent finishing. Inspired by the special wetting phenomena of various biological surfaces in nature, there are more and more related studies on fluorine-free superhydrophobic finishing, mainly focusing on the construction of micro / nano rough structures and the modification of low surface energy components. At present, methods such as plasma treatment, physical etching, photolithography, and template-assisted deposition have been successfully applied to the construction of hydrophobic surfaces. However, these methods often require complex instrument equipment, have cumbersome processes, and are costly, lack universality, and cannot be prepared on a large scale.

[0003] Silicone materials have the advantages of low surface energy (20 - 22 mN / m), high thermal stability, and excellent weather resistance. However, using them alone may not be able to endow the substrate with superhydrophobic effects. Usually, it is necessary to additionally introduce inorganic nanoparticles to construct a low surface energy micro / nano rough surface. However, the wear resistance of this surface is generally poor, and there is also a risk of harm to the human body and the environment caused by the peeling of inorganic nanoparticles during use. Therefore, if a surface with a stable rough structure can be spontaneously formed based on silicone materials, it will show great application value in the field of fluorine-free superhydrophobic textile finishing.

[0004] At present, the methods for constructing self-rough surfaces based on silicone components mainly include: thermally induced phase separation, polarity induced phase separation and solvent induced phase separation. Among them, thermally induced phase separation is mainly based on the difference in solubility of polymers in the same solvent at different curing temperatures to obtain a self-rough structure, but the temperature required for this method is usually high (above 250°C), and conventional equipment is difficult to meet the process requirements. Polarity induced phase separation is mainly based on the polarity difference between polymer components, which causes phase separation to form a non-uniform structure. For example, Chinese patent CN114874697 B discloses a method for preparing a self-rough surface by polarity induced phase separation, which mainly embeds polar segments into non-polar segments, and then uses polarity differences to form phase separation during curing to obtain a self-rough surface. However, this method requires complex chemical synthesis, is time-consuming, and if fluorine-containing components are not introduced, the finished fabric cannot obtain a superhydrophobic effect. Solvent induced phase separation is based on the difference in solubility of polymers in good / bad solvents at the same temperature to form a continuous phase and a dispersed phase, and a self-rough surface is obtained after curing. Such as Chinese patent CN104790206 A discloses a kind of self-roughening porous mesh super-hydrophobic polyester fabric and preparation method thereof, mainly based on polydimethylsiloxane / polyvinyl chloride exchange induced phase separation under mixed solvent system to form self-rough surface, the full solvent system used in the method is relatively harmful to human body and environment, and polyvinyl chloride needs to be additionally introduced, and the air permeability of the fabric after finishing is not evaluated. In summary, the method for constructing a self-rough system based on phase separation is mostly to utilize the difference in solubility of polymer components under different conditions, and there are respective shortcomings, which are difficult to be applied to actual industrial production. In addition, a series of problems such as poor water washability, low stability, and large impact on air permeability existing in existing conventional super-hydrophobic finishing agents also restrict the further development of hydrophobic fabrics.

[0005] Therefore, how to prepare a fluorine-free / nanoparticle-free superhydrophobic finishing agent in an efficient and simple manner, and to achieve the finishing of superhydrophobic fabrics with wear resistance, wash resistance and chemical resistance based on simple operations is a technical difficulty that needs to be urgently solved in this field. Summary of the invention

[0006] The purpose of the present invention is to provide a self-roughening organosilicon super-hydrophobic finishing agent and a preparation method and application thereof. The self-roughening organosilicon super-hydrophobic finishing agent is fluorine-free and avoids the use of inorganic nanoparticles. It has high storage stability and requires a low curing temperature. It can give the fabric an excellent hydrophobic effect and has good wear resistance, wash resistance and chemical resistance, while having little effect on air permeability.

[0007] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0008] The present invention provides a method for preparing a self-roughening organosilicon super-hydrophobic finishing agent, comprising the following steps:

[0009] Mix vinyl silicone oil with a platinum catalyst to obtain a first component;

[0010] Mix vinyl silicone oil, hydrogen-containing silicone oil and an inhibitor to obtain a second component;

[0011] Mix the first component, the second component and a reinforcing agent, carry out an addition reaction, dissolve the obtained organosilicon polymer component in an organic solvent, then add water, and disperse to obtain a self-roughened organosilicon superhydrophobic finishing agent;

[0012] The polarity of the organic solvent < the polarity of water.

[0013] Preferably, the vinyl silicone oil includes terminal vinyl polydimethylsiloxane and / or terminal vinyl polymethylvinylsiloxane; the viscosity of the vinyl silicone oil is 1000 - 100000 mPa·s.

[0014] Preferably, the mass ratio of vinyl silicone oil to platinum catalyst in the first component is 100.5 - 110.5:1.

[0015] Preferably, the hydrogen content of the hydrogen-containing silicone oil is 1.2 - 1.6%; the hydrogen-containing silicone oil is one or both of end-chain hydrogen-containing silicone oil and side-chain hydrogen-containing silicone oil; the inhibitor includes 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane, 1-ethynyl-1-cyclohexanol, 2-methyl-3-butyn-2-ol or 3,7,11-trimethyldodec-3-yne-2-ol.

[0016] Preferably, the mass ratio of vinyl silicone oil, hydrogen-containing silicone oil to inhibitor in the second component is 10.5 - 13.5:6 - 8:1.

[0017] Preferably, the reinforcing agent includes vinyl MQ silicone resin; the M / Q ratio of the vinyl MQ silicone resin is 0.5 - 1.5;

[0018] The vinyl MQ silicone resin includes methyl vinyl MQ silicone resin and / or vinyl phenyl MQ silicone resin;

[0019] The mass ratio of the first component, the second component to the reinforcing agent is 1:1:0.25 - 5.3.

[0020] Preferably, the organic solvent includes one or more of tetrahydrofuran, ethyl acetate, n-hexane, dichloromethane and chloroform.

[0021] Preferably, the mass ratio of water to the organic solvent is 1-4:1; the mass ratio of the component containing the organosilicon polymer to the total mass of the organic solvent and water is 1-1.5:100; the stirring speed for dispersion is 2000-10000 r / min, and the dispersion time is 5-30 min.

[0022] The present invention provides an application of the self-roughened organosilicon superhydrophobic finishing agent prepared by the preparation method described in the above technical solution in fabric waterproof finishing.

[0023] Preferably, after the self-roughened organosilicon superhydrophobic finishing agent is used for fabric finishing by spraying or dipping, and then heated and cured, a self-roughened structure is formed on the fabric surface.

[0024] The present invention provides a preparation method of a self-roughened organosilicon superhydrophobic finishing agent. A first component is obtained by mixing vinyl silicone oil and a platinum catalyst; a second component is obtained by mixing vinyl silicone oil, hydrogen-containing silicone oil and an inhibitor; the first and second components are mixed with a reinforcing agent, then dissolved in an organic solvent and water is added, and the finishing agent is obtained through dispersion. The obtained finishing agent is used for fabric finishing, and a self-roughened structure with a low surface energy can be formed on the fabric surface after heating and curing.

[0025] The method of the present invention first synthesizes a component containing an organosilicon polymer, and then utilizes the difference in solubility parameters of the organosilicon polymer in organic solvents and water with different polarities to cause supersaturation and precipitation, thereby forming a finishing agent. When this finishing agent is used for fabric finishing, heating and curing treatment can be combined to promote rapid cross-linking before the organosilicon droplets are completely diffused on the fabric surface, so as to realize the construction of a self-roughened surface. This finishing agent is fluorine-free and avoids the use of inorganic nanoparticles, has high storage stability, requires a low curing temperature, can endow the fabric with excellent hydrophobic effects (the water contact angle can reach up to 158°), has good wear resistance, wash resistance and chemical stability, and has little influence on air permeability at the same time.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The present invention can realize the construction of a self-roughened structure on the fabric surface only based on low-surface-energy organosilicon materials, without the need to additionally introduce inorganic nanoparticles, avoiding the harm caused by their easy peeling to the human body and the environment.

[0028] Different from the method of phase separation using polydimethylsiloxane / polyvinyl chloride in a mixed solvent system in the prior art, the present invention constructs a water-rich dispersion system based only on silicone materials and realizes the formation of a self-roughened surface through rapid heat treatment (to promote crosslinking and curing), effectively reducing the usage amount of volatile solvents. At the same time, this finishing agent has excellent storage stability (no sedimentation after storing at room temperature for 3 months); compared with traditional hydrophobic finishing agents that require a relatively high curing temperature (≥130°C) for fabric finishing, the self-roughened finishing agent provided by the present invention can achieve crosslinking and curing at a relatively low temperature (80°C is sufficient), with low energy consumption, and can endow the fabric with superhydrophobic effects (the water contact angle can reach up to 158°, and the water wettability grade can reach 5), and has little impact on breathability.

[0029] Furthermore, due to the introduction of vinyl MQ silicone resin, it can be used as a reinforcing agent to increase the crosslinking degree of the system, and can effectively improve the mechanical firmness between the self-roughened silicone superhydrophobic finishing agent and the fabric, thus showing excellent wear resistance, wash resistance and chemical stability.

[0030] The self-roughened silicone superhydrophobic finishing agent provided by the present invention does not contain fluorine, avoiding its potential toxicity and bioaccumulation; the present invention does not require complex chemical synthesis, has a simple preparation process, mild reaction conditions, strong operability, high practical value, and is suitable for large-scale industrial production. Description of the Drawings

[0031] Figure 1 It is the morphology diagram of the self-roughened silicone superhydrophobic finishing agent prepared in Example 1;

[0032] Figure 2 It is the physical photos of the self-roughened silicone superhydrophobic finishing agent prepared in Example 1 before and after storage;

[0033] Figure 3 It is the scanning electron microscope diagram of the aramid fabric before and after finishing with the self-roughened silicone superhydrophobic finishing agent in Example 1;

[0034] Figure 4 It is the hydrophobic effect diagram of different droplets on the aramid fabric finished with the self-roughened silicone superhydrophobic finishing agent;

[0035] Figure 5 It is the contact angle of the aramid fabric finished in Example 1 before and after the tests of wash resistance, wear resistance and chemical stability. Detailed Embodiments

[0036] In the present invention, unless otherwise specified, the raw materials or reagents required for preparation are all commercially available products well-known to those skilled in the art.

[0037] The present invention provides a preparation method of a self-roughened silicone superhydrophobic finishing agent, including the following steps:

[0038] Mix vinyl silicone oil with a platinum catalyst to obtain a first component;

[0039] Mix vinyl silicone oil, hydrogen-containing silicone oil and an inhibitor to obtain a second component;

[0040] Mix the first component, the second component and a reinforcing agent, carry out an addition reaction, dissolve the obtained organosilicon polymer component in an organic solvent, then add water, and disperse to obtain a self-rough organic silicon superhydrophobic finishing agent;

[0041] The polarity of the organic solvent < the polarity of water.

[0042] In the present invention, the vinyl silicone oil preferably includes terminal vinyl polydimethylsiloxane and / or terminal vinyl polymethylvinylsiloxane; the viscosity of the vinyl silicone oil is preferably 1000~100000 mPa·s. When there are two types of vinyl silicone oil as above, the present invention has no special limitation on the ratio of different types of vinyl silicone oil, and any ratio is acceptable.

[0043] The present invention has no special limitation on the source and specific type of the platinum catalyst, and commercially available products well-known in the art can be used; in the examples of the present invention, the platinum catalyst is specifically Karstedt platinum catalyst (5000 ppm, Dongguan Zhongxin Organosilicon Materials Co., Ltd.).

[0044] In the present invention, the mass ratio of vinyl silicone oil to platinum catalyst in the first component is preferably 100.5~110.5:1, more preferably 100.5~105.5:1.

[0045] The present invention has no special limitation on the conditions for mixing the vinyl silicone oil and the platinum catalyst, and the materials can be mixed evenly according to the process well-known in the art; in the examples of the present invention, specifically, mechanical stirring is carried out at a rotation speed of 1200 r / min for 15 min.

[0046] In the present invention, the hydrogen content of the hydrogen-containing silicone oil is preferably 1.2~1.6%; the hydrogen-containing silicone oil is preferably one or both of terminal hydrogen-containing silicone oil and side-chain hydrogen-containing silicone oil; when there are two types of hydrogen-containing silicone oil as above, the present invention has no special limitation on the ratio of different types of hydrogen-containing silicone oil, and any ratio is acceptable.

[0047] In the present invention, the inhibitor preferably includes 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane (CAS No. 2554-06-5), 1-ethynyl-1-cyclohexanol, 2-methyl-3-butyn-2-ol or 3,7,11-trimethyldodec-3-yne-2-ol.

[0048] In the present invention, the mass ratio of vinyl silicone oil, hydrogen-containing silicone oil and inhibitor in the second component is preferably 10.5-13.5:6-8:1, more preferably 11.5-12.5:6-8:1.

[0049] The present invention has no special limitation on the conditions for mixing the vinyl silicone oil, hydrogen-containing silicone oil and inhibitor. The materials can be mixed evenly according to the process well-known in the art; in the examples of the present invention, specifically, mechanical stirring is carried out at a rotation speed of 1200 r / min for 15 min.

[0050] In the present invention, the reinforcing agent preferably includes vinyl MQ silicone resin; the vinyl MQ silicone resin preferably includes methyl vinyl MQ silicone resin and / or vinyl phenyl MQ silicone resin; the M / Q ratio of the vinyl MQ silicone resin is 0.5-1.5. When the vinyl MQ silicone resin is two of the above, the present invention has no special limitation on the ratio of different types of vinyl MQ silicone resins, and any ratio is acceptable.

[0051] In the present invention, the mass ratio of the first component, the second component and the reinforcing agent is preferably 1:1:0.25-5.3, more preferably 1:1:0.6-5.3, and further preferably 1:1:0.86-2.

[0052] In the present invention, vinyl silicone oil and hydrogen-containing silicone oil react under the action of a catalyst. In the second component, due to the presence of an inhibitor, it can be stored stably. After mixing the first component (containing a catalyst) and the second component, a polymerization reaction occurs to form a polymer; at the same time, both the reinforcing agent vinyl MQ silicone resin and vinyl silicone oil contain double bonds and will undergo an addition reaction with the silicon-hydrogen bond in the hydrogen-containing silicone oil. Introducing a reinforcing agent into the organosilicon polymer in the present invention can increase the stability of the self-rough structure and make the performance of the finishing agent better.

[0053] In the present invention, the organic solvent preferably includes one or more of tetrahydrofuran, ethyl acetate, n-hexane, dichloromethane and chloroform; when the organic solvent is two or more of the above, the present invention has no special limitation on the ratio of different types of organic solvents, and any ratio is acceptable.

[0054] In the present invention, the mass ratio of water to the organic solvent is preferably 1-4:1, more preferably 2.33-4:1; the mass ratio of the component containing the organosilicon polymer to the total mass of the organic solvent and water is preferably 1-1.5:100, more preferably 1.03-1.43:100, and further preferably 1.03-1.33:100.

[0055] The present invention has no special limitation on the conditions for mixing the first component, the second component and the reinforcing agent, and the materials can be mixed evenly according to the processes well-known in the art; in the embodiments of the present invention, specifically, stirring is carried out for 30 s under the condition of 1200 r / min.

[0056] The present invention preferably dissolves the mixture obtained by mixing the first component, the second component and the reinforcing agent in an organic solvent, adds water, and performs dispersion. In the present invention, the stirring speed for the dispersion is preferably 2000 - 10000 r / min, more preferably 4000 - 5000 r / min, the dispersion time is preferably 5 - 30 min, more preferably 8 - 10 min.

[0057] The present invention provides an application of the self-roughened organosilicon superhydrophobic finishing agent prepared by the preparation method described in the above technical solution in fabric waterproof finishing.

[0058] In the present invention, the self-roughened organosilicon superhydrophobic finishing agent is preferably used for fabric finishing by spraying or dipping, and after heat curing, a self-roughened structure is formed on the fabric surface.

[0059] The present invention has no special limitation on the specific composition of the spraying or dipping, and the self-roughened organosilicon superhydrophobic finishing agent can be directly used for fabric finishing according to the spraying or dipping methods well-known in the art.

[0060] In the present invention, the number of times of heat curing preferably corresponds to the number of times of spraying or dipping. After each spraying or dipping is completed, heat curing is carried out; the temperature for each heat curing is independently preferably 60 - 90 °C, more preferably 70 - 80 °C, and the time is preferably 30 min. After all spraying or dipping is completed, the time for continuing heat curing is preferably 2 h. The present invention promotes the volatilization of the solvent and water by heating to achieve the crosslinking and curing of the self-roughened organosilicon finishing agent.

[0061] In the present invention, the fabric is preferably pure cotton, cotton-polyester, aramid, polyimide or their blended fabrics. The present invention has no special limitation on the specific specifications and sources of the fabric, and the corresponding fabrics well-known in the art can be used.

[0062] The following examples are used to illustrate in detail the technical solutions provided by the present invention, but they should not be construed as limiting the protection scope of the present invention.

[0063] In the following examples, the terminal vinyl polydimethylsiloxane is from Zhejiang Xinan Chemical Industry Group Co., Ltd. (XHG - 206), the platinum catalyst is Kast platinum catalyst (5000 ppm, Dongguan Zhongxin Organosilicon Materials Co., Ltd.); the hydrogen - containing silicone oil is from Zhejiang Xinan Chemical Industry Group Co., Ltd. (XHG - 202), the inhibitor (2,4,6,8 - tetramethyl - 2,4,6,8 - tetravinylcyclotetrasiloxane) is from Shanghai Aladdin Biochemical Technology Co., Ltd. (≥97%), and the methyl vinyl MQ silicone resin is from Zhejiang Xinan Chemical Industry Group Co., Ltd. (Wynca - 5325); the aramid fabric is from Beijing Bangwei Protective Textile Co., Ltd. (M53610A).

[0064] Example 1

[0065] The preparation method of the self - roughing organosilicon super - hydrophobic finishing agent provided in this example includes the following steps:

[0066] Under room - temperature conditions, weigh 50.25 g of terminal vinyl polydimethylsiloxane (viscosity 1000 mPa·s) and 0.5 g of platinum catalyst (5000 ppm) into a beaker, and mechanically stir at a speed of 1200 r / min for 15 min until evenly mixed to obtain the first component;

[0067] Put 37.75 g of terminal vinyl polydimethylsiloxane (viscosity 100000 mPa·s), 18 g of hydrogen - containing silicone oil (hydrogen content 1.6%) and 3 g of inhibitor (2,4,6,8 - tetramethyl - 2,4,6,8 - tetravinylcyclotetrasiloxane) into a beaker, and stir at a speed of 1200 r / min for 15 min to obtain the second component;

[0068] Construction of a water - rich system: Weigh 10 g of the first component and the second component in a mass ratio of 1:1, add 3.3 g of methyl vinyl MQ silicone resin (M / Q ratio is 0.71), stir at 1200 r / min for 30 s, and dissolve the obtained mixture in 300 g of tetrahydrofuran; separately take 700 g of deionized water and inject it into the above - mentioned mixture under high - speed stirring conditions (4000 r / min), disperse for 10 min to obtain the self - roughing organosilicon super - hydrophobic finishing agent;

[0069] Spray the self - roughing organosilicon super - hydrophobic finishing agent prepared in Example 1 onto the aramid fabric. Conditions for each spraying: spraying pressure 0.1 bar, distance from the spray gun nozzle to the fabric 10 cm, spraying amount per spraying 0.2 mL / cm 2 , spray 4 times in total. After each spraying, immediately cure at 80 °C for 30 min, and extend the drying time of the last time to 2 h to obtain the finished fabric.

[0070] Example 2

[0071] The preparation method of the self-roughened silicone superhydrophobic finishing agent provided in this example specifically includes the following steps:

[0072] The preparation methods of the first component and the second component are the same as those in Example 1;

[0073] Weigh 10 g of the first component and the second component in a mass ratio of 1:1, then add 1.3 g of methyl vinyl MQ silicone resin (M / Q ratio is 0.71), stir for 30 s under the condition of 1200 r / min, and dissolve the obtained mixture in 300 g of tetrahydrofuran; separately take 700 g of deionized water and inject it into the above mixture under the condition of high-speed stirring (4000 r / min), and disperse for 10 min to obtain the self-roughened silicone superhydrophobic finishing agent;

[0074] Spray the self-roughened silicone superhydrophobic finishing agent onto the aramid fabric, and the spraying method is the same as that in Example 1.

[0075] Example 3

[0076] The preparation method of the self-roughened silicone superhydrophobic finishing agent provided in this example specifically includes the following steps:

[0077] The preparation methods of the first component and the second component are the same as those in Example 1;

[0078] Weigh 10 g of the first component and the second component in a mass ratio of 1:1, then add 3.3 g of methyl vinyl MQ silicone resin (MQ ratio is 0.71), stir for 30 s under the condition of 1200 r / min, and further dissolve it fully in 500 g of tetrahydrofuran; separately take 500 g of deionized water and inject it into the above mixture under the condition of high-speed stirring (4000 r / min), and disperse for 10 min to obtain the self-roughened silicone superhydrophobic finishing agent;

[0079] Spray the self-roughened silicone superhydrophobic finishing agent onto the aramid fabric, and the spraying method is the same as that in Example 1.

[0080] Example 4

[0081] The preparation method of the self-roughened silicone superhydrophobic finishing agent provided in this example specifically includes the following steps:

[0082] The preparation methods of the first component and the second component and the construction method of the water-rich system are the same as those in Example 1;

[0083] Spray the self-roughened silicone superhydrophobic finishing agent onto the aramid fabric. According to the spraying conditions in Example 1, spray 4 times in total. After each spraying, immediately cure at 60 °C for 30 min, and extend the drying time of the last time to 2 h to obtain the finished fabric.

[0084] Example 5

[0085] The preparation method of the self-roughened organosilicon superhydrophobic finishing agent provided in this example specifically includes the following steps:

[0086] The preparation methods of the first component and the second component and the construction method of the water-rich system are the same as those in Example 1;

[0087] Spray the self-roughened organosilicon superhydrophobic finishing agent onto the aramid fabric. According to the spraying conditions in Example 1, spray a total of 6 times. After each spraying, immediately cure at 80 °C for 30 min, and extend the drying time of the last time to 2 h to obtain the finished fabric.

[0088] Example 6

[0089] The preparation method of the self-roughened organosilicon superhydrophobic finishing agent provided in this example specifically includes the following steps:

[0090] The preparation methods of the first component and the second component are the same as those in Example 1;

[0091] Weigh 10 g of the first component and the second component in a mass ratio of 1:1, then add 4.3 g of methyl vinyl MQ silicone resin (M / Q ratio is 1.0) and stir at 1200 r / min for 30 s. Dissolve the obtained mixture in 300 g of ethyl acetate; separately take 700 g of deionized water and inject it into the above mixture under high-speed stirring conditions (5000 r / min). After dispersing for 8 min, obtain the self-roughened organosilicon superhydrophobic finishing agent;

[0092] Spray the self-roughened organosilicon superhydrophobic finishing agent onto the aramid fabric. The spraying method is the same as that in Example 1.

[0093] Example 7

[0094] The preparation method of the self-roughened organosilicon superhydrophobic finishing agent provided in this example specifically includes the following steps:

[0095] At room temperature, weigh 55.25 g of vinyl-terminated polydimethylsiloxane (3000 mPa·s) and 0.5 g of platinum catalyst (5000 ppm) in a beaker, and mechanically stir at a rotation speed of 1200 r / min for 15 min until evenly mixed to obtain the first component;

[0096] Place 32.75 g of vinyl-terminated polydimethylsiloxane (50,000 mPa·s), 24 g of hydrogen-containing silicone oil (hydrogen content 1.2%), and 3 g of inhibitor (2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane) in a beaker, and stir at a speed of 1200 r / min for 15 min until evenly mixed to obtain the second component;

[0097] The method for constructing the water-rich system is the same as that in Example 1;

[0098] Immerse the aramid fabric in the self-roughened organosilicon superhydrophobic finishing agent in Example 7 for 30 min, and the drying temperature is 80 °C. First, dry for 2 h, and then continue to dry for 2 h.

[0099] Characterization and testing

[0100] 1) Observe the morphology of the self-roughened organosilicon superhydrophobic finishing agent prepared in Example 1 through a metallographic polarizing microscope, Figure 1 It can be seen that the dispersed droplets are uniformly spherical and there is no agglomeration phenomenon.

[0101] 2) Figure 2 Shown are the physical photos of the self-roughened organosilicon superhydrophobic finishing agent prepared in Example 1 before and after storage. As can be seen from Figure 2 it, after storing at room temperature for 3 months, the appearance of the self-roughened organosilicon superhydrophobic finishing agent is almost the same as its initial state, without sedimentation, indicating its good storage stability.

[0102] 3) Figure 3 Shown are the scanning electron microscope images of the aramid fabric before and after being finished with the self-roughened organosilicon superhydrophobic finishing agent in Example 1. It can be found from Figure 3 it that compared with the un-finished aramid fabric, an irregular rough structure has been generated on the fiber surface of the finished aramid fabric, indicating that the organosilicon finishing agent has been successfully loaded on the fabric surface. Combining the low surface energy characteristics of the organosilicon component and the construction of the self-roughened surface, the finished aramid fabric will exhibit good superhydrophobic effects.

[0103] 4) Figure 4 Shown are the hydrophobic effect diagrams of different droplets on the aramid fabric finished with the self-roughened organosilicon superhydrophobic finishing agent; among them, the tea is white hair silver needle tea water, the juice is commercially available Huiyuan orange juice, the milk is commercially available Mengniu pure milk, the coffee is commercially available Nestle coffee brewing solution, the cola is commercially available Coca-Cola, and the water is tap water; as can be seen from Figure 4 it, a variety of droplets can stably remain on the aramid fabric treated with the self-roughened organosilicon superhydrophobic finishing agent without spreading, indicating that the hydrophobic performance of the finished fabric is excellent.

[0104] 5) Conduct performance tests on the finished fabric:

[0105] The contact angle of the finished fabric was tested according to GB / T 42694-2023; the moisture resistance of the finished fabric was tested according to GB / T 4745-2012; the finished fabric was washed according to GB / T 8629-2017; the air permeability of the finished fabric was tested according to GB / T 5453-1997.

[0106] The abrasion resistance of the finished aramid fabric was tested. Test conditions: The sample was placed on 800-mesh sandpaper, a 100-g weight was placed on the upper surface of the fabric, and then the fabric was moved horizontally along the sandpaper at a speed of 7.5 cm / s for 15 cm, and then moved in the opposite direction to the starting point, which was recorded as one cycle.

[0107] The chemical stability of the finished aramid fabric was tested. Test conditions: The sample was immersed in acid (HCl, pH = 1), base (NaOH, pH = 12), and salt (NaCl, pH = 7) solutions for 24 h.

[0108] Figure 5 The contact angles of the finished aramid fabric in Example 1 before and after the washing resistance, abrasion resistance, and chemical stability tests.

[0109] The test results show that:

[0110] The water contact angle of the finished aramid fabric in Example 1 was 158° ( Figure 5 ), and the surface water wettability grade was 5; after 10 washes, the water contact angle was 151°, and the surface water wettability grade was 4-5, indicating that it had good superhydrophobic effect, anti-wetting property, and wash resistance; the air permeability rates of the aramid fabric before and after finishing were 435 mm / s and 394 mm / s respectively, indicating that the rough-type silicone finishing agent had little effect on the air permeability of the fabric.

[0111] The water contact angle of the finished fabric sample in Example 1 was 152° after 400 friction cycles, indicating that it had good abrasion resistance.

[0112] Even in a harsh acid or base environment, the finished fabric sample in Example 1 still exhibited a relatively high water contact angle (acid - 150°, base - 152°, salt - 153°), indicating its excellent chemical stability.

[0113] Compared with Example 1, the finished aramid fabric in Example 2 still has superhydrophobic effect (water contact angle is 156°), but after 10 washes, the water contact angle drops to 125°, and the surface water wettability level drops to Grade 3; in addition, after abrasion resistance and chemical stability tests, the water contact angle of the sample also decreases significantly (the water contact angle is less than 140°). This is mainly because methyl vinyl MQ silicone resin can act as a reinforcing agent, which can participate in the addition reaction between terminal vinyl polydimethylsiloxane and hydrogen-containing silicone oil, improve the crosslinking degree, and thus effectively improve the mechanical firmness of the self-roughened silicone finishing agent. However, the introduction amount of methyl vinyl MQ silicone resin in Example 2 is relatively low, and the crosslinking degree of the system is insufficient, resulting in a decrease in abrasion resistance and chemical stability.

[0114] Although the finished aramid fabric in Example 3 still has superhydrophobic effect (water contact angle is 151°), it is lower compared with Example 1. This is because one of the construction mechanisms of the self-roughened system is due to the difference in solubility parameters of polysiloxane segments in water and non-polar solvents. When only non-polar solvents are used as dispersants, the silicone components can be well dispersed; with the addition of deionized water, the solubility of the solution in the silicone components decreases, and it precipitates due to supersaturation, and finally forms a finishing agent dispersion after dispersion. In Example 1, the mass ratio of deionized water to tetrahydrofuran is 7:3, while in Example 3, the mass ratio of deionized water to tetrahydrofuran is reduced to 1:1. Since the proportion of deionized water in Example 3 is relatively small and the degree of supersaturation is insufficient, the number of droplets in the dispersion is small and the particle size is small, which is not conducive to the formation of a rough surface, thus affecting the superhydrophobic performance.

[0115] Although the finished aramid fabric in Example 4 still has relatively high hydrophobic effect (water contact angle is 145°, surface water wettability level is Grade 4), it is significantly lower compared with Example 1. This is because the construction of the self-roughened system is on the one hand due to the formation of micro / nano droplets in the water-rich system, and on the other hand, it is necessary to promote the rapid crosslinking of silicone droplets at a relatively high temperature, so as to solidify on the fiber surface before the droplets are completely diffused to form a self-roughened structure. Compared with Example 1, the curing temperature in Example 4 is relatively low (60°C), which is not conducive to the rapid crosslinking and curing of droplets, thus affecting the construction of the rough surface and resulting in a decrease in hydrophobic effect.

[0116] The water contact angle of the finished aramid fabric in Example 5 is 157°, and the surface water wettability level is Grade 5. After 10 washes, the water contact angle is 153°, and the surface water wettability level is Grade 4 - 5, mainly because the increase in spraying times improves the wash resistance.

[0117] The water contact angle of the finished aramid fabric in Example 6 is 158°, and the surface water wettability level is Grade 5. After 10 washes, the water contact angle is 152°, and the surface water wettability level is Grade 4 - 5, which is similar to the test results of Example 1.

[0118] In Example 7, the water contact angle of the finished aramid fabric is 155°, and the surface water repellency grade is 5. After washing 10 times, the water contact angle is 150°, and the surface water repellency grade is 4-5, indicating that through the finishing method of impregnation, the fabric can also be given good hydrophobic effect.

[0119] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A preparation method of a self-roughening type organosilicon superhydrophobic finishing agent, characterized in that It includes the following steps: Mix vinyl silicone oil with a platinum catalyst to obtain a first component; Mix vinyl silicone oil, hydrogen-containing silicone oil and an inhibitor to obtain a second component; Mix the first component, the second component and a reinforcing agent, carry out an addition reaction, dissolve the obtained organosilicon polymer component in an organic solvent, then add water, and disperse to obtain a self-roughened organosilicon superhydrophobic finishing agent; The polarity of the organic solvent < the polarity of water; The reinforcing agent includes vinyl MQ silicone resin; the M / Q ratio of the vinyl MQ silicone resin is 0.5 to 1.5; the vinyl MQ silicone resin includes methyl vinyl MQ silicone resin; The mass ratio of the first component, the second component and the reinforcing agent is 1:1:0.25 to 2; The mass ratio of water to the organic solvent is 1 to 4:

1.

2. The preparation method according to claim 1, characterized in that, The vinyl silicone oil includes terminal vinyl polydimethylsiloxane and / or terminal vinyl polymethylvinylsiloxane; the viscosity of the vinyl silicone oil is 1000 to 100000 mPa·s.

3. The preparation method according to claim 1, characterized in that, The mass ratio of vinyl silicone oil to platinum catalyst in the first component is 100.5 to 110.5:

1.

4. The preparation method according to claim 1, characterized in that, The hydrogen content of the hydrogen-containing silicone oil is 1.2 to 1.6%; The hydrogen-containing silicone oil is one or both of end-chain hydrogen-containing silicone oil and side-chain hydrogen-containing silicone oil; the inhibitor includes 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane, 1-ethynyl-1-cyclohexanol, 2-methyl-3-butyn-2-ol or 3,7,11-trimethyldodec-3-yne-2-ol.

5. The preparation method according to claim 1 or 4, characterized in that, The mass ratio of vinyl silicone oil, hydrogen-containing silicone oil and inhibitor in the second component is 10.5 to 13.5:6 to 8:

1.

6. The preparation method according to claim 1, characterized in that, The organic solvent includes one or more of tetrahydrofuran, ethyl acetate, n-hexane, dichloromethane and chloroform.

7. The preparation method according to claim 1 or 6, characterized in that, The mass ratio of the organosilicon polymer component to the total mass of the organic solvent and water is 1 to 1.5:100; the stirring speed for dispersion is 2000 to 10000 r / min, and the dispersion time is 5 to 30 min.

8. The self-roughened organosilicon superhydrophobic finishing agent prepared by the preparation method according to any one of claims 1 to 7.

9. The application of the self-roughened organosilicon superhydrophobic finishing agent according to claim 8 in fabric waterproof finishing. After the self-roughened organosilicon superhydrophobic finishing agent is used for fabric finishing by spraying or impregnation and then heated and cured, a self-roughened structure is formed on the fabric surface.

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