Acetylene carbon black of bridged modified fiber as well as preparation method and application of acetylene carbon black

Abstract

The invention discloses acetylene carbon black of bridging modified fiber and a preparation method and application of the acetylene carbon black, the preparation method comprises the following steps: 1, 6-diisocyanate, hydroxyl functional fiber and acetylene carbon black are blended according to the mass ratio of (0.05-0.5): (1-20): 100 for reaction, and the acetylene carbon black is obtained. According to the invention, 1, 6-diisocyanate and hydroxyl-functionalized fibers are adopted to modify acetylene carbon black, the hydroxyl-functionalized fibers with excellent length-diameter ratio and acetylene carbon black with hydroxyl functional groups are bridged under the connection of the 1, 6-diisocyanate, acetylene carbon black is loaded on the hydroxyl-functionalized fibers, and the 1, 6-diisocyanate and the hydroxyl-functionalized fibers are mixed to form the composite material. Isocyanate groups in the 1, 6-diisocyanate have high activity, when the 1, 6-diisocyanate reacts with a hydroxyl compound, polyamino methyl ester can be generated, and the polyamino methyl ester has high strength and rigidity, can bear large force, has good wear resistance and corrosion resistance, keeps stable performance after being used for a long time, and can be used for a long time. The acetylene carbon black can be firmly loaded on the surface of the hydroxyl functional fiber, so that the compatibility of the material is enhanced.

Description

Technical Field

[0001] The invention relates to acetylene carbon black material, in particular to acetylene carbon black for bridging modified fibers, a preparation method thereof, and an application of the acetylene carbon black for improving the compatibility of the acetylene carbon black with a semiconductive tape. Background Art

[0002] In the core link of power cable manufacturing, the role of semi-conductive tape cannot be underestimated. It is not only the key to improving the electrical performance of the cable, but also the cornerstone to ensure the long-term stable operation of the cable. Acetylene black, with its excellent conductive properties, occupies a pivotal position in the preparation of high-performance semi-conductive tape. However, although acetylene black has excellent performance, it faces challenges such as uneven dispersion, poor stability and easy agglomeration. These problems directly affect the performance of the tape and even the entire cable.

[0003] To solve these problems, the scientific research community is actively engaged in the modification research of acetylene carbon black, aiming to improve its compatibility with other materials. With the rapid development of nanotechnology, researchers have cleverly applied nanotechnology to the modification of acetylene carbon black. By constructing a fine nano protective layer on the surface of carbon black and utilizing the unique performance of nano additives, they have effectively resisted the erosion of carbon black by the harsh environment, significantly improved its dispersion stability, ensured the uniform distribution of acetylene carbon black in the semi-conductive tape, and thus enhanced the overall electrical performance of the cable. But at the same time, the introduction of nano additives also brings new challenges, such as the risk of material shedding and possible environmental pollution problems, which urgently need to be addressed by the scientific and industrial communities. On the other hand, physical modification methods such as ball milling and ultrasonic treatment are also showing the potential for acetylene carbon black particle refinement in continuous exploration, aiming to achieve more optimized particle size and distribution, thereby improving its performance. However, although these methods are effective, they are often accompanied by limitations such as high energy consumption, rising costs and limited compatibility improvement, which restricts their widespread application in industrial production. Summary of the invention

[0004] In view of the problems of poor compatibility and pollution in the current modification methods of acetylene carbon black, the present invention provides an acetylene carbon black for bridge-modified fibers, a preparation method and application thereof. The novel preparation method can firmly load acetylene carbon black on the surface of hydroxyl functionalized fibers, significantly improve its dispersion stability, and improve the compatibility of semiconductor electrical packages. Secondly, the added isocyanate group can react with the hydroxyl group on the fiber to form a urea group, reducing the problem of material powder loss.

[0005] In order to achieve the above-mentioned object, the present invention provides a method for preparing acetylene carbon black for bridge-modified fibers, which comprises the following steps: 1,6-diisocyanate, hydroxyl functionalized fiber and acetylene carbon black in a mass ratio of (0.05-0.5):(1-20):100 are mixed and reacted to obtain acetylene carbon black for bridge-modified fibers.

[0006] The modification principle of acetylene carbon black is as follows: the hydroxyl groups on the hydroxyl functionalized fiber can be easily connected with the isocyanate groups on 1, 6-diisocyanate, and bridged under the connection of 1, 6-diisocyanate, so that acetylene carbon black can be modified (such as Figure 2 As shown). Acetylene carbon black can not only be firmly loaded onto the hydroxyl functionalized fiber, but the hydroxyl groups on the surface can also be converted into isocyanate groups. The modified acetylene carbon black then forms urea groups with the amide groups on the semi-conductive tape, thereby improving the compatibility of acetylene carbon black and the semi-conductive tape. (As shown Figure 3 as shown).

[0007] The hydroxyl functionalized fiber has a large specific surface area and can produce a larger contact area than other materials. The isocyanate group in 1, 6-diisocyanate is highly active. When it reacts with hydroxyl compounds, it can generate polyurethane, which has high strength and stiffness, can withstand large forces, has good wear resistance and corrosion resistance, maintains stable performance after long-term use, has high elasticity, and can return to its original shape after being deformed by pressure. It is precisely because of the generation of this polyurethane that acetylene carbon black can be firmly loaded on the surface of hydroxyl functionalized fibers, significantly improving the uniform distribution of acetylene carbon black in the semi-conductive tape and further enhancing the compatibility of the material.

[0008] Preferably, the mass ratio of the 1,6-diisocyanate, the hydroxyl functionalized fiber and the acetylene black is 0.5:10:100.

[0009] Preferably, the hydroxyl functionalized fiber is selected from carbon fiber, glass fiber, and cellulose nanofiber. Its characteristic is that the surface is rich in hydroxyl groups, and the interface bonding performance with the matrix material can be improved through chemical modification (such as coupling agent treatment, grafting reaction).

[0010] Preferably, the length of the hydroxyl functionalized fiber is 50 to 400 microns. Short fibers have better dispersibility.

[0011] Specifically, the reaction temperature is 50 to 150 o C, reaction time is 0.5 ~ 3 h.

[0012] The second aspect of the present invention provides acetylene carbon black obtained by the above-mentioned preparation method, which has the following structural formula: .

[0013] The third aspect of the present invention provides the use of the above-mentioned acetylene black in preparing a semiconductive tape of a cable.

[0014] Through the above technical solution, the present invention achieves the following beneficial effects: 1. The present invention uses 1,6-diisocyanate and hydroxyl functionalized fiber to modify acetylene carbon black. The hydroxyl functionalized fiber with excellent aspect ratio and the acetylene carbon black with hydroxyl functional group are bridged under the connection of 1,6-diisocyanate, and the acetylene carbon black is loaded on the hydroxyl functionalized fiber. Since acetylene carbon black usually exists in the form of fine particles, these particles may have a chain or grape-like structure and have a high specific surface area. This structure enables acetylene carbon black to form good dispersion and close contact when mixed with other materials. In addition, the apparent density of acetylene carbon black is relatively low, usually between 0.2 and 0.3 g / cm 3 This makes it lighter than the semiconductor packs on the market. And because acetylene carbon black is connected by 1,6-diisocyanate with a certain length, it is more evenly dispersed and less likely to cause powder loss.

[0015] 2. Because the carrier is hydroxyl functionalized fiber, it has high tensile strength and tensile modulus, and is not easy to deform and break when bearing load. Its strength is more than 4 times that of aluminum alloy, and its modulus can also reach a very high level. It also has good corrosion resistance and wear resistance, and can maintain a long service life in complex environments.

[0016] 3. Acetylene carbon black can not only be loaded onto hydroxyl functionalized fibers and is not easy to fall off; at the same time, the hydroxyl groups on the surface can also be converted into isocyanate groups. The modified acetylene carbon black then forms urea groups with the amide groups on the semi-conductive tape. The reaction yield is very high, and the generated urea groups can firmly adhere to the semi-conductive tape, thereby improving the compatibility of acetylene carbon black and the semi-conductive tape.

[0017] 4. In the present invention, 1,6-diisocyanate, hydroxyl functionalized fiber and acetylene carbon black are easy to react, the reaction process is pollution-free, the reaction process is simple and easy, and no by-products are discharged.

[0018] 5. The prepared modified acetylene carbon black is compounded with the colloid, and then coated on the semi-conductive tape. The tensile test is carried out by a tensile testing machine. It takes a force of nearly 50N to pull it apart, which shows that the compatibility of the two is relatively good.

[0019] 6. The present invention can solve the problem of powder shedding of the semi-conductive tape, and can be used to prepare semi-conductive tapes for high-voltage and ultra-high-voltage cables with better performance, thus having great application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The figure is a display photograph of the dispersed microscopic morphology of acetylene black of bridge-modified carbon fiber prepared by the method of Example 1 of the present invention and Comparative Example 1; Figure 2 This is a reaction flow chart of preparing acetylene black for bridge-modified carbon fiber prepared by the method of Example 1 of the present invention; Figure 3 It is a chemical connection diagram between acetylene black and semi-conductive tape of bridge-modified carbon fiber prepared by the method of Example 1 of the present invention. DETAILED DESCRIPTION

[0021] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0022] Example 1 1,6-diisocyanate, carbon fiber (length 200 μm) and acetylene black in a mass ratio of 0.5:5:100 were placed in a reactor at a temperature of 90 o C for 1.5 h to obtain a multifunctional modified acetylene carbon black.

[0023] Embodiments 2 to 3: The same steps as in Example 1 were adopted, except that the mass ratio of 1,6-diisocyanate, carbon fiber and acetylene black was changed (see the table below).

[0024]

[0025] Embodiments 4 to 6: The same procedure as in Example 1 was used, only the reaction temperature was changed (see the table below).

[0026]

[0027] Embodiments 7 to 9: The same steps as in Example 1 were used, only the reaction time was changed (see the table below).

[0028]

[0029] Embodiment 10 to example 12: The same steps as in Example 1 were followed, only the mass of the carbon fibers was changed (see the table below).

[0030]

[0031] Embodiment 13 to Example 14: The same steps as in Example 1 were followed, except that the carbon fibers were replaced (see the table below).

[0032]

[0033] Comparative Example 1 The other conditions were the same as in Example 1, except that the reaction temperature was adjusted to 40 o C.

[0034] Comparative Example 2 The other conditions were the same as in Example 1, except that the reaction temperature was adjusted to 200 o C.

[0035] Comparative Example 3 The other conditions were the same as in Example 1, except that the reaction time was adjusted to 0.4 h.

[0036] Comparative Example 4 The other conditions were the same as in Example 1, except that the reaction time was adjusted to 4 h.

[0037] Comparative Example 5 Other conditions are the same as in Example 1, except that carbon fiber is not used.

[0038] Comparative analysis: The acetylene black obtained in the above embodiments and comparative examples was compounded with a colloid (50% acrylic acid solution and acetylene black were blended in a mass ratio of 1:3 and stirred evenly).

[0039] like Figure 1 As shown, after the bridged modified acetylene carbon black obtained in Example 1 is blended with the conductive colloid, it has a very uniform dispersion distribution and excellent compatibility with the semi-conductive tape. However, after the bridged modified acetylene carbon black obtained in Comparative Example 1 is blended with the colloid, it has an uneven dispersion distribution and poor compatibility with the semi-conductive tape.

[0040] In addition, the powder drop rate (1 kg iron ball falls freely from a height of 1 m and hits a 2 The compatibility was evaluated by the mass percentage of acetylene carbon black falling off / total acetylene carbon black filled in the center of the finished semi-conductive tape. The following table is a comparison table of the compatibility of the samples prepared in the above embodiments and comparative examples.

[0041]

[0042] From the table above we can see that: 1) The reaction temperature of 1,6-diisocyanate, carbon fiber and acetylene black is particularly critical. When the temperature is too low or too high, the powder loss rate of the obtained material is high. This is because the reaction temperature is too low, the reaction conditions are not sufficient, and the reaction cannot proceed. When the reaction temperature is too high, the product degrades. o C, the obtained material has the lowest powder loss rate, which means that the prepared bridged modified acetylene carbon black has the best compatibility.

[0043] 2) When the mass ratio of carbon fiber and acetylene black is 0.5:10:100, 1,6-diisocyanate, carbon fiber and acetylene black can react completely with the lowest powder loss rate; when carbon fiber is not used, acetylene black has no place to be loaded, the compatibility is greatly reduced, and the powder loss rate is high.

[0044] 3) When the reaction time is less than 0.5 h, the carbon fiber hardly reacts and the powder loss rate also presents a higher value. When the reaction time is too long, the powder loss rate is limited, resulting in energy waste.

[0045] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0046] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0047] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for preparing acetylene carbon black for bridging modified fibers, characterized in that: The method comprises the following steps: 1,6-diisocyanate, hydroxyl functionalized fiber and acetylene carbon black in a mass ratio of (0.05-0.5):(1-20):100 are mixed and reacted to obtain acetylene carbon black with fiber modified by diisocyanate bridge.

2. The preparation method according to claim 1, characterized in that The mass ratio of the 1,6-diisocyanate, the hydroxyl functionalized fiber and the acetylene carbon black is 0.5:10:

100.

3. The preparation method according to claim 1, characterized in that: The hydroxyl functionalized fibers are selected from carbon fibers, glass fibers, and cellulose nanofibers.

4. The preparation method according to claim 1, characterized in that: The length of the hydroxyl functionalized fiber is 50 to 400 microns.

5. The preparation method according to claim 1, characterized in that The reaction temperature is 50 ~ 150 o C, reaction time is 0.5 ~ 3 h.

6. Acetylene carbon black prepared by the preparation method according to any one of claims 1 to 5, characterized in that: It has the following structural formula: 。 7. Use of the acetylene black according to claim 6 in preparing a semi-conductive tape for a cable.

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