Hydrophobic modification liquid, preparation method thereof and hydrophobic non-woven fabric

Abstract

The invention relates to the field of medium-voltage cable water resistance, in particular to hydrophobic modification liquid, a preparation method thereof and hydrophobic non-woven fabric. The hydrophobic modification liquid comprises the following components in parts by weight: 24-96 parts of an organic solvent; 1 to 10 parts of long-chain alkyl trimethoxy silane; 1-2 parts of a dispersant; 1-2 parts of an emulsifier; 1-3 parts of an organosilicon compound; and 10-20 parts of an acidic adjusting liquid. By utilizing the hydrolysis characteristic of long-chain alkyltrimethoxysilane in an organic solvent, micron-sized particles with low-surface-energy alkyl chains on the surfaces can be generated, and the micron-sized particles can be efficiently and compactly filled in the surface of an attachment and an internal gap structure by virtue of the micron-sized characteristic of the micron-sized particles; a stable and uniform super-hydrophobic modified layer is formed through dual effects of physical adsorption and chemical anchoring, and finally, lasting and reliable hydrophobic performance and core function improvement of blocking liquid water permeation are realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of medium voltage cable water resistance, in particular to a hydrophobic modified liquid and its preparation method, and a hydrophobic non-woven fabric. BACKGROUND

[0002] In the precise structure of medium voltage single-core cable, the copper tape shield plays a crucial role. It not only serves as a barrier to electromagnetic interference, but also is the key to maintaining the uniform distribution of the electric field inside the cable and protecting the main insulation layer. After completing the copper tape shielding process, a layer of non-woven fabric is usually tightly wrapped around the outside as an outer protective layer. The main design intention of traditional non-woven fabric in this application is to provide basic physical protection: it can effectively block the intrusion of dust and particulate matter in the external environment, buffer the slight mechanical friction, extrusion or scratches that may occur during laying or running, prevent these physical factors from directly damaging the sensitive copper tape shield and the structure below, and provide the necessary protection during the initial stages of cable manufacturing, transportation and installation.

[0003] However, traditional non-woven fabric has a significant and fatal shortcoming in water resistance. Its essence is a non-woven material made of synthetic fibers (such as polyester, polypropylene, etc.) bonded by physical or chemical methods, and its structural feature is the presence of a large number of micron to sub-micron level disordered pore networks. This open structure allows water molecules (whether liquid water or water vapor) to easily penetrate through the non-woven fabric barrier. Many non-woven fabric materials themselves have a certain hydrophilicity, or the fiber surface is easy to adsorb environmental moisture, further exacerbating the penetration of water. When the cable is laid or runs in a humid environment with high humidity, rain or easy water accumulation underground, water will penetrate through this "loose" non-woven fabric protective layer and reach the copper tape shield wrapped inside. The shielding copper tape is easily affected by water molecules in the environment and oxidized, thereby affecting the service life of the entire cable.

[0004] Therefore, the skilled person in the art is committed to developing a hydrophobic modified liquid with water resistance and hydrophobicity, its preparation method and a hydrophobic non-woven fabric. SUMMARY

[0005] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present application is to provide a hydrophobic modified liquid and its preparation method, and a hydrophobic non-woven fabric.

[0006] To achieve the above-mentioned purpose, the present application provides a hydrophobic modified liquid, which comprises the following components by weight:

[0007] Organic solvent 24-96 parts;

[0008] Long-chain alkyl trimethoxysilane 1-10 parts;

[0009] Dispersant 1-2 parts;

[0010] 1-2 parts of emulsifier;

[0011] 1-3 parts of organosilicon compound;

[0012] 10-20 parts of acidic regulating liquid.

[0013] Preferably, the organic solvent is anhydrous ethanol or anhydrous propanol.

[0014] Preferably, the long-chain alkyltrimethoxysilane is one or more of hexadecyltrimethoxysilane, octadecyltrimethoxysilane and dodecyltrimethoxysilane.

[0015] Preferably, the dispersant is sodium dodecylbenzenesulfonate or sodium dodecyl sulfate.

[0016] Preferably, the emulsifier is prepared by mixing polysorbate 80 or sorbitan monooleate and deionized water in a mass ratio of 0.8-1.2:8-12.

[0017] Preferably, the organosilicon compound is one or more of dimethyl silicone oil and hydroxy silicone oil.

[0018] Preferably, the acidic regulating liquid is prepared by mixing citric acid or dilute hydrochloric acid and deionized water in a mass ratio of 0.8-1.2:40-60.

[0019] The present invention also provides a method for preparing any of the above-mentioned hydrophobically modified liquids, comprising the following steps:

[0020] S1, mixing an organic solvent and long-chain alkyltrimethoxysilane in proportion;

[0021] S2. Add a dispersant to the mixed solution formed in step S1 and stir evenly;

[0022] S3, adding an emulsifier to the mixed solution formed in step S2 and stirring uniformly;

[0023] S4, adding organosilicon compound to the mixed solution formed in step S3 and stirring uniformly;

[0024] S5. Gradually add the acidic adjustment solution to the mixed solution formed in step S4 and continue stirring until the mixed solution becomes a milky white suspension;

[0025] S6. When the mixed solution in step S5 becomes a milky white suspension, continue stirring for 15-25 minutes to complete the preparation.

[0026] The present invention also provides a hydrophobic non-woven fabric, which is treated with any of the above-mentioned hydrophobic modification liquids.

[0027] Preferably, the hydrophobic modification liquid is sprayed on the front and back of the ordinary non-woven fabric 2-5 times each to obtain the result.

[0028] The beneficial effect of the present invention is that the present invention utilizes the hydrolysis characteristics of long-chain alkyltrimethoxysilane in organic solvents to generate micron-sized particles with low surface energy alkyl chains on the surface. Particles, due to their micron-scale characteristics, can be efficiently and densely filled on the surface of the attached object and in the internal gap structure, forming a stable and uniform super-hydrophobic modification layer through the dual effects of physical adsorption and chemical anchoring, ultimately achieving long-lasting and reliable hydrophobic performance and improving the core function of blocking liquid water penetration. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the production process of the hydrophobic modified liquid of the present invention.

[0030] Figure 2 It is a diagram of the hydrophobic principle of the hydrophobic modified liquid in the present invention.

[0031] Figure 3 This is a diagram showing the actual hydrophobic effect of the hydrophobic nonwoven fabric in a specific embodiment of the present invention.

[0032] Figure 4 This is a graph showing the anti-friction test of the hydrophobic nonwoven fabric in one embodiment of the present invention.

[0033] Figure 5 The hydrophobic nonwoven fabric is Figure 4 Actual photos of the contact angle of water droplets at different friction times in the experiment.

[0034] Figure 6 The hydrophobic nonwoven fabric is Figure 4 Data analysis chart under different loads (30g, 40g, 50g, 60g, 70g) in the experiment.

[0035] Figure 7 This is a graph showing the tensile strength of existing common non-woven fabrics.

[0036] Figure 8 1 is a graph showing the tensile strength of a hydrophobic nonwoven fabric according to a specific embodiment of the present invention.

[0037] Figure 9 This is a schematic diagram of the infiltration of existing ordinary non-woven fabrics after fire resistance testing.

[0038] Figure 10 Schematic diagram of the infiltration of the hydrophobic nonwoven fabric after the fire resistance test in one embodiment of the present invention. DETAILED DESCRIPTION

[0039] The present invention will be further described below with reference to the accompanying drawings and examples. In this example, unless otherwise stated, all raw materials used are commercially available.

[0040] Examples 1-3 are the preparation of a hydrophobic modified liquid of the present invention.

[0041] like Figure 1 As shown, the preparation of the hydrophobic modified liquids of Examples 1-3 is carried out according to the following steps, the difference being the specific selection and amount of various raw materials. The preparation steps specifically include:

[0042] 1) Mix the organic solvent and long-chain alkyltrimethoxysilane in proportion and stir until they are completely dissolved.

[0043] In this step, the organic solvent is anhydrous ethanol or anhydrous propanol.

[0044] The long-chain alkyltrimethoxysilane is one or more of hexadecyltrimethoxysilane, octadecyltrimethoxysilane and dodecyltrimethoxysilane.

[0045] 2) Add a dispersant to the mixed solution formed in step S1 and stir evenly.

[0046] In this step, the dispersant is sodium dodecylbenzenesulfonate or sodium dodecyl sulfate, and the silicone oil is dispersed by adding the dispersant.

[0047] 3) Add an emulsifier to the mixed solution formed in step S2 and stir evenly.

[0048] In this step, the emulsifier is prepared by mixing polysorbate 80 or sorbitan monooleate and deionized water in a mass ratio of 1:10.

[0049] 4) Add the organosilicon compound to the mixed solution formed in step S3 and stir evenly.

[0050] In this step, the organosilicon compound is one or more of dimethyl silicone oil and hydroxy silicone oil.

[0051] 5) Slowly add an acidic regulating solution to the mixed solution formed in step S4 to adjust the pH value of the solution and continue stirring until the mixed solution becomes a milky white suspension.

[0052] In this step, the acidic adjustment liquid is prepared by mixing solid citric acid or dilute hydrochloric acid and deionized water in a mass ratio of 1:50, and is used to adjust the acidity and alkalinity of the hydrophobic modification liquid.

[0053] 6) When the mixed solution in step S5 becomes a milky white suspension, continue stirring for 15-25 minutes to complete the preparation.

[0054] The selection of ingredients for Examples 1-3 is shown in Table 1, and the amounts of each ingredient for Examples 1-3 are shown in Table 2

[0055] Table 1

[0056] Serial number organic solvents Long-chain alkyltrimethoxysilane dispersants emulsifiers Organosilicon compounds Acidic regulating fluid Example 1 Anhydrous ethanol Octadecyltrimethoxysilane Sodium lauryl sulfate Sorbitan monooleate Dimethicone dilute hydrochloric acid Example 2 Anhydrous ethanol Hexadecyltrimethoxysilane Sodium dodecylbenzenesulfonate Polysorbate 80 Dimethicone Citric acid Example 3 Anhydrous propyl alcohol Hexadecyltrimethoxysilane Sodium dodecylbenzenesulfonate Polysorbate 80 Hydroxy silicone oil Citric acid

[0057] Table 2 The amount of each component in units.

[0058] Serial number organic solvents Long-chain alkyltrimethoxysilane dispersants emulsifiers Organosilicon compounds Acidic regulating fluid Example 1 24 1 1 1 1 10 Example 2 60 5 2 1 2 15 Example 3 96 10 2 2 3 20

[0059] like Figure 2-3 As shown, the present invention utilizes the hydrolysis characteristics of long-chain alkyltrimethoxysilane in organic solvents to generate micron-sized particles with low surface energy alkyl chains on the surface. Particles, due to their micron-scale characteristics, can be efficiently and densely filled on the surface of the attached object and in the internal gap structure, forming a stable and uniform super-hydrophobic modification layer through the dual effects of physical adsorption and chemical anchoring, ultimately achieving long-lasting and reliable hydrophobic performance and improving the core function of blocking liquid water penetration.

[0060] The present invention also provides a kind of hydrophobic non-woven fabric processed by hydrophobic modification liquid as described above, and specific processing steps are: spray 2-5 times of the aforementioned hydrophobic modification liquid on the front and back of common non-woven fabric and obtain after drying at room temperature for 2h-4h.Specific to the present embodiment, taking conventional non-woven fabric with width 6cm and length 100cm as example, spray 3 times on the front and back of the non-woven fabric, the interval time of 3 sprayings is 30min, and each spraying amount is controlled at 1-2mL, and after spraying, drying at room temperature for 3h, preparation can be completed.In other embodiments, the spraying amount suitable for it and its corresponding spraying interval time and drying time can be selected according to the actual size of the non-woven fabric.By wrapping the hydrophobic non-woven fabric after treatment around the outside of the cable, the copper tape shielding layer is isolated from the water molecules in the external environment, thereby achieving the effect of copper tape anti-corrosion.

[0061] In order to further illustrate that the non-woven fabric treated with the hydrophobic modification liquid of the present invention has extremely high stability, in this application, the hydrophobic modification liquid prepared in Example 2 was used to treat the existing non-woven fabric and the following experiments were conducted to verify its performance.

[0062] The experiment content is as follows:

[0063] Experiment 1: Anti-friction test

[0064] Friction test methods such as Figure 4As shown, by applying different loads (30g, 40g, 50g, 60g, 70g of weights) on the hydrophobic non-woven fabric and slowly pulling it at a uniform speed to make it move back and forth on the friction paper, each load is repeated five times, and after each friction, the optical contact angle measuring instrument is used to drop water on the hydrophobic non-woven fabric and measure the surface water droplet contact angle. In specific implementation, the optical contact angle measuring instrument can be selected as DROP-METER-A-200, and other products of the same type can also be selected in other embodiments. To further show the experimental effect, taking the 50g weight as an example, Figure 5 The water droplet contact angles corresponding to the five consecutive friction experiments of the hydrophobic non-woven fabric under the load of 50g weights are recorded from top to bottom, and the specific friction experiment data of the remaining loads are as shown in Figure 6 The above results show that the surface hydrophobic contact angle of the hydrophobic non-woven fabric prepared in the present application decays very little after repeated friction, which confirms that it has excellent anti-friction ability and hydrophobic durability.

[0065] Experiment Two: Tensile Strength Test

[0066] In this experiment, in order to further show the performance of the hydrophobic non-woven fabric of the present application, a commercially available ordinary non-woven fabric is introduced for comparison.

[0067] Before the experiment, the commercially available ordinary non-woven fabric and the hydrophobic non-woven fabric of the present application are cut into rectangular samples with a length of 27cm and a width of 1cm. Then the two ends of the commercially available ordinary non-woven fabric sample are placed on the clamps of the tensile tester, and after being ready, the tensile tester is started and stretched to the straight state to start the test. The measurement data is as shown in Figure 7 With the gradual increase of the tensile force, the tensile strength of the ordinary non-woven fabric reaches an extreme value of 77.397N, and then the tensile strength decreases sharply and finally breaks. Taking the same experimental steps, the experimental data of the hydrophobic non-woven fabric of the present application is as shown in Figure 8 The tensile strength of the hydrophobic non-woven fabric of the present application reaches an extreme value of 91.426N, which is significantly higher than that of the commercially available ordinary non-woven fabric.

[0068] In specific implementation, commercially available tensile testers can be selected, such as AI-7000-SU1, (SANS) CMT4104, (MTS) Criterion® E43 series, etc.

[0069] The above experimental data show that after the surface of the ordinary non-woven fabric is modified to be hydrophobic, the tensile strength can be significantly improved. And the modified hydrophobic treatment does not have a negative impact on the material strength, which can meet the tensile strength requirements in industrial applications.

[0070] Experiment Three: Fire Resistance Test

[0071] To verify the change of the temperature resistance of the non-woven fabric after being sprayed with the hydrophobic modification liquid, the conventional non-woven fabric and the modified non-woven fabric were placed in an oven at 200℃ for 5 hours, and then taken out. The surfaces of the two non-woven fabrics were observed and photographed. Further, the water contact angle of the two samples was measured by using an optical contact instrument. Among them, Figure 9 and Figure 10 are the conventional non-woven fabric and the non-woven fabric modified by the hydrophobic modification liquid of the present application, respectively. It is observed that the water drop infiltration speed on the non-woven fabric modified by the hydrophobic modification liquid of the present application is still much smaller than that of the conventional non-woven fabric. Therefore, it can be concluded that the hydrophobic treatment of the conventional non-woven fabric improves the high temperature resistance of the conventional non-woven fabric to a certain extent.

[0072] From the above tests and comparisons, it can be concluded that the non-woven fabric treated by the hydrophobic modification liquid of the present application has stable mechanical properties and industrial value, and the hydrophobic modification liquid of the present application has high adaptability, wide application field and great market promotion value.

[0073] The above describes the preferred embodiments of the present application in detail. It should be understood that those skilled in the art can make many modifications and changes without creative labor according to the concept of the present application. Therefore, any technical solution obtained by logical analysis, reasoning or limited experiment based on the prior art according to the concept of the present application shall be within the protection scope defined by the claims.

Claims

1. A hydrophobic modified liquid, characterized in that The invention comprises the following components in parts by weight: 24-96 parts of organic solvent; 1-10 parts of long-chain alkyltrimethoxysilane; 1-2 parts of dispersant; 1-2 parts of emulsifier; 1-3 parts of organosilicon compound; and 10-20 parts of acidic regulating liquid.

2. The hydrophobic modified liquid according to claim 1, wherein: The organic solvent is anhydrous ethanol or anhydrous propanol.

3. The hydrophobic modified liquid according to claim 2, wherein: The long-chain alkyltrimethoxysilane is one or more of hexadecyltrimethoxysilane, octadecyltrimethoxysilane and dodecyltrimethoxysilane.

4. The hydrophobic modified liquid according to claim 1, 2 or 3, wherein: The dispersant is sodium dodecylbenzenesulfonate or sodium dodecyl sulfate.

5. The hydrophobic modified liquid according to claim 1, wherein: The emulsifier is prepared by mixing polysorbate 80 or sorbitan monooleate and deionized water in a mass ratio of 0.8-1.2:8-12.

6. The hydrophobic modified liquid according to claim 1, wherein: The organic silicon compound is one or more of dimethyl silicone oil and hydroxy silicone oil.

7. The hydrophobic modified liquid according to claim 1, wherein: The acidic regulating liquid is prepared by mixing citric acid or dilute hydrochloric acid and deionized water in a mass ratio of 0.8-1.2:40-60.

8. A method for preparing the hydrophobic modified liquid according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1, mixing an organic solvent and long-chain alkyltrimethoxysilane in proportion; S2. Add a dispersant to the mixed solution formed in step S1 and stir evenly; S3, adding an emulsifier to the mixed solution formed in step S2 and stirring uniformly; S4, adding organosilicon compound to the mixed solution formed in step S3 and stirring uniformly; S5. Gradually add the acidic adjustment solution to the mixed solution formed in step S4 and continue stirring until the mixed solution becomes a milky white suspension; S6. When the mixed solution in step S5 becomes a milky white suspension, continue stirring for 15-25 minutes to complete the preparation.

9. A hydrophobic nonwoven fabric, characterized in that: The hydrophobic nonwoven fabric is treated with the hydrophobic modification liquid according to any one of claims 1 to 7.

10. The hydrophobic nonwoven fabric according to claim 9, wherein: The hydrophobic modification liquid is sprayed on the front and back of ordinary non-woven fabrics 2-5 times.

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