Insulating paste resistant to high-temperature extrusion deformation and preparation method thereof

Abstract

The invention relates to the technical field of cable rubber, in particular to high-temperature extrusion deformation resistant insulating glue and a preparation method thereof.The high-temperature extrusion deformation resistant insulating glue is prepared from, by weight, 50-80 parts of ethylene propylene rubber, 20-50 parts of butadiene rubber, 60-80 parts of calcined clay, 30-40 parts of talcum powder, 10-30 parts of modified white carbon black, 4-8 parts of paraffin oil, 1-2 parts of a flow dispersing aid and 0.3-0.5 part of a coupling agent. 2.5-3.0 parts of a vulcanizing agent, 0.5-1 part of a crosslinking aid and 0.5-1 part of an anti-aging agent. The vulcanization activity and the crosslinking density of the insulating blend rubber can be remarkably improved, so that the insulating rubber has high elasticity, high hardness and high strength, and the high-temperature extrusion deformation resistance of the insulating rubber is effectively improved.

Description

Technical Field

[0001] The present application relates to the technical field of cable rubber, and in particular to an insulating rubber resistant to high temperature extrusion deformation and a preparation method thereof. Background Art

[0002] At present, the cable production process generally includes conductor (power line) processing, insulation layer extrusion, cable assembly, shielding layer production, sheath extrusion and other processes. The insulation layer extrusion process is to extrude insulation glue on the surface of the wire core through an extruder, and form an insulation layer after vulcanization. After vulcanization, the surface is usually smooth and round, and there is no extrusion deformation between the wire cores or embossing on the insulation surface; in the cable assembly process, since it is usually carried out at room temperature, there is no extrusion deformation or embossing on the surface of the power line insulation layer. However, in the sheath extrusion process, when the cable core is extruded with a sheath and continuously vulcanized at high temperature and high pressure to make the finished product, after stripping the sheath, it is found that there are obvious extrusion deformation marks at the twisting of the power line insulation layer. If there is a metal braided layer for shielding on the surface of the insulation layer, there will also be embossing of the braided layer.

[0003] When the insulation layer of the power line is squeezed and deformed, the actual thickness of the power line section will be less than the minimum thickness required by the cable standard, resulting in failure. In severe cases, the cable is prone to breakdown and cannot pass the pressure test; even worse, when the cable is bent during use, the insulation layer is flattened and the surface is unevenly stressed, causing the power line insulation to crack, directly leading to the scrapping of the cable and even endangering the safety of personnel and equipment. The above problems have become common problems that need to be solved in the cable industry.

[0004] In view of the above-mentioned related technologies, the present application develops an insulating adhesive resistant to high temperature extrusion deformation and a preparation method thereof. Summary of the invention

[0005] In order to prevent the power line insulation layer from being squeezed and deformed and flattened during the production process of the cable, thereby improving the qualified rate of finished cables and also improving the safety and reliability of the cables, the present application provides an insulating glue that is resistant to high-temperature extrusion deformation.

[0006] In the first aspect, the present application provides an insulating adhesive resistant to high temperature extrusion deformation, which adopts the following technical solution:

[0007] An insulating rubber resistant to high-temperature extrusion deformation is prepared from the following raw materials in parts by weight: 50-80 parts of ethylene-propylene rubber, 20-50 parts of butadiene rubber, 60-80 parts of calcined clay, 30-40 parts of talcum powder, 10-30 parts of white carbon black, 4-8 parts of paraffin oil, 1-2 parts of a flow dispersing agent, 0.3-0.5 parts of a coupling agent, 2.5-3.0 parts of a vulcanizing agent, 0.5-1 parts of a cross-linking agent, and 0.5-1 parts of an RD antioxidant.

[0008] By adopting the above technical solution, EPDM rubber is used as the base rubber material, and there is no polar group in the molecular structure. It can effectively prevent the passage of electric current, prevent electrical equipment from leakage, short circuit, etc., ensure the safety and stability of the line, and is a good high-voltage insulating material.

[0009] At the same time, EPDM has good tolerance to heat, light, ozone and chemicals, can maintain good insulation performance for a long time, and extend the service life of the insulating glue; as a blended rubber, butyl rubber has high elasticity and flexibility, so that the insulating glue will not break easily under different working environments, such as low temperature, bending, stretching and other external forces, and can maintain a complete insulation structure. At the same time, butyl rubber can be well mixed with other ingredients in the insulating glue formula, such as fillers and plasticizers, which helps to optimize the comprehensive performance of the insulating glue, so that the various ingredients can work synergistically and improve the overall quality and performance of the insulating glue; calcined clay can increase the hardness and strength of the insulating glue, so that it can better resist external pressure and wear, absorb and disperse heat, and improve the thermal stability of the insulating glue to a certain extent, preventing it from aging too quickly or performance degradation in high temperature environments; talcum powder itself is a good electrical insulator. Adding it to the insulating glue can effectively improve the dielectric properties of the insulating glue and enhance its resistance to electric fields. It can also reduce the absorption of water by the insulating glue and prevent the reduction of insulation performance due to water intrusion. At the same time, talcum powder can adjust the rheological properties of the insulating glue, making the glue more uniform and smooth during the application and pouring processes; white carbon black has a significant reinforcing effect on the insulating glue, which can improve the tensile strength, tear strength and wear resistance of the glue, making the insulating glue tougher and more durable; paraffin oil can be used as a plasticizer to increase the flexibility of the insulating glue, so that the glue can maintain good elasticity under different temperature conditions and prevent it from becoming brittle and hard. Paraffin oil can also reduce the viscosity of the insulating glue and improve its fluidity.

[0010] Preferably, the ethylene propylene rubber is EPDM4045.

[0011] By adopting the above technical solution, EPDM4045 is an ethylene propylene diene monomer rubber synthesized by metallocene catalysis, which has good processing performance and low temperature performance, excellent aging resistance, insulation performance and chemical corrosion resistance, and is an insulating rubber material with good comprehensiveness.

[0012] Preferably, the butadiene rubber is BR9000.

[0013] By adopting the above technical solution and taking advantage of the outstanding wear resistance of BR9000, the insulation layer can maintain good performance in a long-term friction environment, reduce wear and extend service life. At the same time, BR9000 has both high elasticity and cold resistance, and good vulcanization activity, which significantly improves the comprehensive performance of the insulation layer.

[0014] Preferably, the white carbon black is modified white carbon black particles whose surfaces are grafted with a coupling agent.

[0015] By adopting the above technical scheme, some functional groups on the coupling agent are used to chemically react with a large number of hydroxyl groups on the surface of silica, thereby changing the group structure and distribution on the surface of silica, forming a "bridge" between silica and the polymer matrix, thereby improving the compatibility of silica with EPDM rubber and butyl rubber, significantly improving the compatibility of the blended rubber, and making the mechanical properties of the blended rubber more excellent.

[0016] Preferably, the modified silica is ultrafine silica with a particle size range of 10-30 nm.

[0017] By adopting the above technical solution, the ultrafine white carbon black has a very small particle size and a large specific surface area, which can fully contact with the rubber molecules and form a strong bond, significantly improving the tensile strength, tear strength and wear resistance of the rubber. Small particle size and large specific surface area are helpful for the mixing and molding of rubber, making the fluidity of the rubber compound better, reducing energy consumption and equipment wear during processing, and improving production efficiency. At the same time, it can also increase the hardness, wear resistance and corrosion resistance of the insulating rubber layer, improve the adhesion of the rubber layer to the substrate, and enhance the protective performance.

[0018] Preferably, the coupling agent is A172.

[0019] By adopting the above technical solution, coupling agent A172 is a bifunctional molecule that can react with both inorganic fillers and organic polymers. This bifunctional reactivity enables them to improve the bonding, adhesion and compatibility between inorganic materials and organic polymers through two-way chemical reactions, thereby improving the mechanical properties of rubber-based composite materials.

[0020] Preferably, the vulcanizing agent is dicumyl peroxide DCP.

[0021] By adopting the above technical solution, dicumyl peroxide DCP is a highly efficient rubber vulcanizing agent. On the one hand, during the vulcanization process, the free radicals generated by the decomposition of DCP can react with active sites such as double bonds in the rubber molecular chain, so that a cross-linked network structure is formed between the rubber molecular chains, thereby improving the physical properties of the rubber, such as tensile strength, hardness, elastic modulus, etc. can be significantly improved. On the other hand, vulcanization with dicumyl peroxide DCP can achieve co-vulcanization of two rubbers, so that the properties of the two rubbers can be combined after blending.

[0022] Preferably, the cross-linking aid is TAIC.

[0023] By adopting the above technical solutions, TAIC can promote the cross-linking between rubber molecular chains and make the cross-linking network more complete, thereby enhancing the physical properties of rubber products, such as improving tensile strength and tear strength, improving the aging resistance of rubber, and making rubber products more resistant to ozone, ultraviolet rays and heat aging during long-term use.

[0024] In a second aspect, a method for preparing an insulating adhesive resistant to high temperature extrusion deformation adopts the following technical scheme, including the following preparation steps:

[0025] S1 rubber mixing mill XK-160, roller distance 1mm, add EPDM and BR, plasticize and thin for 5-8 times;

[0026] S2 adjusts the roller distance to 2mm, adds a thin blending rubber roll, and sequentially adds crosslinking agent, antioxidant, flow dispersing agent, and coupling agent. After rolling 3 / 4 around 3 times, alternately add clay, talcum powder, white carbon black, and paraffin oil. After the feeding is completed, roll 3 / 4 around 3 times.

[0027] S3 adds vulcanizing agent, and after the feeding is completed, adjusts the roller distance to 1mm, makes triangle packs 5-8 times, and adjusts the roller distance to 2mm to produce sheets to form a blend of EPDM rubber and cis-1,4-butadiene rubber.

[0028] By adopting the above technical solution, the qualification rate and preparation efficiency of the insulating glue can be improved, the hardness and strength of the insulating glue can be guaranteed, and the high-temperature extrusion deformation resistance of the insulating glue can be significantly improved.

[0029] Preferably, the vulcanized rubber preparation parameters in step S3 are: a flat plate vulcanizer temperature of 170-200° C., a pressure of 10-15 MPa, a vulcanization time of 15-30 min, and a vulcanized sheet size of 140 mm×120 mm×1 mm.

[0030] By adopting the above technical solution, the stability and continuity of the colloid vulcanization process can be improved, and the vulcanization uniformity and product strength of the vulcanized rubber can be improved.

[0031] In summary, the present application includes at least one of the following beneficial technical effects:

[0032] 1. By blending EPDM and BR, the vulcanization activity of the insulating blend is improved, the cross-linking density is increased, and high elasticity is obtained;

[0033] 2. By adding modified white carbon black, calcined clay, and talcum powder, and then after surface treatment with coupling agent A172, they react and combine with rubber during vulcanization, thereby improving the hardness and strength of the insulating blended rubber, and effectively improving the high temperature extrusion deformation resistance of the insulating rubber;

[0034] 3. The production process of the present invention is stable, easy to operate, energy-saving and consumption-reducing, and suitable for large-scale continuous production. DETAILED DESCRIPTION

[0035] The present application is further described in detail below with reference to the embodiments.

[0036] Example

[0037] Example 1

[0038] An insulating adhesive resistant to high-temperature extrusion deformation of the present embodiment includes the following components in parts by weight: 50 parts of ethylene propylene rubber EPDM4045, 50 parts of butadiene rubber BR9000, 80 parts of calcined clay, 40 parts of talcum powder, 10 parts of modified white carbon black with a particle size of 10-30 nm, 4 parts of paraffin oil, 1 part of a flow and dispersion aid, 0.3 parts of a coupling agent A172, 2.5 parts of a vulcanizing agent DCP, 0.5 parts of a cross-linking aid TAIC, and 1 part of an antioxidant RD.

[0039] The modified silica preparation method in this embodiment includes the following preparation steps:

[0040] S01 is added to the reaction kettle, and a 30% concentration of ethanol aqueous solution is added as the reaction system;

[0041] S02 Add white carbon black and coupling agent in a weight ratio of 30:5 into the reactor, control the reaction temperature to 130°C, the stirring speed to 400rpm, and the reaction time to 1 hour;

[0042] After the reaction is completed, the modified silica particles are obtained by vacuuming and drying with a distillation device.

[0043] The present embodiment provides a method for preparing an insulating adhesive resistant to high temperature extrusion deformation, comprising the following preparation steps:

[0044] S1 rubber mixing mill XK-160, roller distance 1mm, add EPDM and BR, plasticize and thin for 5 times;

[0045] S2 adjusts the roller distance to 2mm, adds a thin blending rubber roll, and sequentially adds crosslinking agent, antioxidant, flow dispersing agent, and coupling agent. After rolling 3 / 4 around 3 times, alternately add clay, talcum powder, white carbon black, and paraffin oil. After the feeding is completed, roll 3 / 4 around 3 times.

[0046] S3 adds vulcanizing agent, and after the feeding is completed, adjust the roller distance to 1mm, make triangle packs 5 times, and adjust the roller distance to 2mm to make a blend of EPDM and BR. The temperature of the flat vulcanizer is 170℃, the pressure is 10MPa, the vulcanization time is 30min, and the size of the vulcanized sheet is 140mm×120mm×1mm.

[0047] Example 2

[0048] An insulating adhesive resistant to high-temperature extrusion deformation of the present embodiment includes the following components in parts by weight: 50 parts of ethylene propylene rubber EPDM4045, 50 parts of butadiene rubber BR9000, 80 parts of calcined clay, 40 parts of talcum powder, 10 parts of modified white carbon black with a particle size of 10-30 nm, 4 parts of paraffin oil, 1.5 parts of a flow and dispersion aid, 0.3 parts of a coupling agent A172, 2.5 parts of a vulcanizing agent DCP, 0.5 parts of a cross-linking aid TAIC, and 1 part of an antioxidant RD.

[0049] The modified silica preparation method in this embodiment includes the following preparation steps:

[0050] S01 is added to the reaction kettle, and a 30% concentration of ethanol aqueous solution is added as the reaction system;

[0051] S02 Add white carbon black and coupling agent in a weight ratio of 30:5 into the reactor, control the reaction temperature to 130°C, the stirring speed to 400rpm, and the reaction time to 1 hour;

[0052] After the reaction is completed, the modified silica particles are obtained by vacuuming and drying with a distillation device.

[0053] The present embodiment provides a method for preparing an insulating adhesive resistant to high temperature extrusion deformation, comprising the following preparation steps:

[0054] S1 rubber mixing mill XK-160, roller distance 1mm, add EPDM and BR, plasticize and thin for 6 times;

[0055] S2 adjusts the roller distance to 2mm, adds a thin blending rubber roll, and sequentially adds crosslinking agent, antioxidant, flow dispersing agent, and coupling agent. After rolling 3 / 4 around 3 times, alternately add clay, talcum powder, white carbon black, and paraffin oil. After the feeding is completed, roll 3 / 4 around 3 times.

[0056] S3 adds vulcanizing agent, after the feeding is completed, adjust the roller distance to 1mm, make triangle packs 6 times, adjust the roller distance to 2mm to make a blend of EPDM and BR. The temperature of the flat vulcanizer is 180℃, the pressure is 12MPa, the vulcanization time is 25min, and the size of the vulcanized sheet is 140mm×120mm×1mm.

[0057] Example 3

[0058] An insulating adhesive resistant to high-temperature extrusion deformation of the present embodiment includes the following components in parts by weight: 60 parts of ethylene propylene rubber EPDM4045, 40 parts of butadiene rubber BR9000, 70 parts of calcined clay, 35 parts of talcum powder, 20 parts of modified white carbon black with a particle size of 10-30 nm, 6 parts of paraffin oil, 1.8 parts of a flow and dispersion aid, 0.4 parts of a coupling agent A172, 2.8 parts of a vulcanizing agent DCP, 0.8 parts of a cross-linking aid TAIC, and 0.8 parts of an antioxidant RD.

[0059] The modified silica preparation method in this embodiment includes the following preparation steps:

[0060] S01 is added to the reaction kettle, and a 30% concentration of ethanol aqueous solution is added as the reaction system;

[0061] S02 Add white carbon black and coupling agent in a weight ratio of 30:5 into the reactor, control the reaction temperature to 130°C, the stirring speed to 400rpm, and the reaction time to 1 hour;

[0062] After the reaction is completed, the modified silica particles are obtained by vacuuming and drying with a distillation device.

[0063] The present embodiment provides a method for preparing an insulating adhesive resistant to high temperature extrusion deformation, comprising the following preparation steps:

[0064] S1 rubber mixing mill XK-160, roller distance 1mm, add EPDM and BR, plasticize and thin for 7 times;

[0065] S2 adjusts the roller distance to 2mm, adds a thin blending rubber roll, and sequentially adds crosslinking agent, antioxidant, flow dispersing agent, and coupling agent. After rolling 3 / 4 around 3 times, alternately add clay, talcum powder, white carbon black, and paraffin oil. After the feeding is completed, roll 3 / 4 around 3 times.

[0066] S3 adds vulcanizing agent, and after the feeding is completed, adjust the roller distance to 1mm, make triangle packs 7 times, and adjust the roller distance to 2mm to make a blend of EPDM and BR. The temperature of the flat vulcanizer is 190℃, the pressure is 13MPa, the vulcanization time is 20min, and the size of the vulcanized sheet is 140mm×120mm×1mm.

[0067] Example 4

[0068] An insulating adhesive resistant to high-temperature extrusion deformation of the present embodiment includes the following components in parts by weight: 80 parts of ethylene propylene rubber EPDM4045, 20 parts of butadiene rubber BR9000, 60 parts of calcined clay, 30 parts of talcum powder, 30 parts of modified white carbon black with a particle size of 10-30 nm, 8 parts of paraffin oil, 2 parts of a flow and dispersion aid, 0.5 parts of a coupling agent A172, 3 parts of a vulcanizing agent DCP, 1 part of a cross-linking aid TAIC, and 0.5 parts of an antioxidant RD.

[0069] The modified silica preparation method in this embodiment includes the following preparation steps:

[0070] S01 is added to the reaction kettle, and a 30% concentration of ethanol aqueous solution is added as the reaction system;

[0071] S02 Add white carbon black and coupling agent in a weight ratio of 30:5 into the reactor, control the reaction temperature to 130°C, the stirring speed to 400rpm, and the reaction time to 1 hour;

[0072] After the reaction is completed, the modified silica particles are obtained by vacuuming and drying with a distillation device.

[0073] The present embodiment provides a method for preparing an insulating adhesive resistant to high temperature extrusion deformation, comprising the following preparation steps:

[0074] S1 rubber mixing mill XK-160, roller distance 1mm, add EPDM and BR, plasticize and thin for 8 times;

[0075] S2 adjusts the roller distance to 2mm, adds a thin blending rubber roll, and sequentially adds crosslinking agent, antioxidant, flow dispersing agent, and coupling agent. After rolling 3 / 4 around 3 times, alternately add clay, talcum powder, white carbon black, and paraffin oil. After the feeding is completed, roll 3 / 4 around 3 times.

[0076] S3 adds vulcanizing agent, and after the feeding is completed, adjust the roller distance to 1mm, make triangle packs 8 times, and adjust the roller distance to 2mm to make a sheet of EPDM and BR blended rubber. The temperature of the flat vulcanizer is 200℃, the pressure is 15MPa, the vulcanization time is 15min, and the size of the vulcanized sheet is 140mm×120mm×1mm.

[0077] Comparative Example

[0078] Comparative Example 1

[0079] An insulating adhesive resistant to high-temperature extrusion deformation, which is different from Example 3 in that: no modified white carbon black is added.

[0080] Comparative Example 2

[0081] An insulating adhesive resistant to high temperature extrusion deformation, which is different from Example 3 in that commercially available white carbon black, brand YHGFEE, with a particle size of 200-300 nm, is added.

[0082] Performance Testing

[0083] Relevant performance tests were conducted on the insulating adhesives resistant to high temperature extrusion deformation prepared in Examples 1-4 and Comparative Examples 1-2, and the results are listed in Table 1.

[0084] Table 1 Performance test results

[0085]

[0086] It can be seen from the above table that the room temperature Shore A hardness of Examples 1-4 of the present invention reaches more than 85, and the high temperature Shore A hardness reaches more than 70, which has obvious improvement advantages over Comparative Examples 1-2. The basic principle is that modified silica is added to the raw material formula. After the silica is modified, it has good compatibility with both EPDM rubber and butadiene rubber, significantly improves the compatibility of the blended rubber, and makes the mechanical properties of the blended rubber more excellent.

[0087] It can also be seen from the above table that the tensile strength, elongation at break, insulation layer appearance and other test results of Examples 1-4 of the present invention are significantly better than those of Comparative Examples 1 and 2, indicating that the embodiments of the present invention are more excellent.

[0088] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. An insulating adhesive resistant to high temperature extrusion deformation, characterized in that: The invention is prepared from the following raw materials in parts by weight: 50-80 parts of ethylene-propylene rubber, 20-50 parts of butadiene rubber, 60-80 parts of calcined clay, 30-40 parts of talc, 10-30 parts of white carbon black, 4-8 parts of paraffin oil, 1-2 parts of flow and dispersion aid, 0.3-0.5 parts of coupling agent, 2.5-3.0 parts of vulcanizing agent, 0.5-1 parts of cross-linking aid and 0.5-1 parts of RD antioxidant.

2. The insulating adhesive resistant to high temperature extrusion deformation according to claim 1, characterized in that: The ethylene propylene rubber is EPDM4045.

3. The insulating adhesive resistant to high temperature extrusion deformation according to claim 1, characterized in that: The butadiene rubber is BR9000.

4. The insulating adhesive resistant to high temperature extrusion deformation according to claim 1, characterized in that: The white carbon black is modified white carbon black particles whose surfaces are grafted and modified by a coupling agent.

5. The insulating adhesive resistant to high temperature extrusion deformation according to claim 4, characterized in that: The modified white carbon black is ultrafine white carbon black with a particle size range of 10-30 nm.

6. The insulating adhesive resistant to high temperature extrusion deformation according to claim 4, characterized in that: The coupling agent is A172.

7. The insulating adhesive resistant to high temperature extrusion deformation according to claim 1, characterized in that: The vulcanizing agent is dicumyl peroxide DCP.

8. The insulating adhesive resistant to high temperature extrusion deformation according to claim 1, characterized in that: The cross-linking aid is TAIC.

9. A method for preparing the insulating adhesive resistant to high temperature extrusion deformation according to claims 1-8, characterized in that: The method comprises the following preparation steps: S1 rubber mixing mill XK-160, roller distance 1mm, add EPDM and BR, plasticize and thin for 5-8 times; S2 adjusts the roller distance to 2mm, adds a thin blending rubber roll, and sequentially adds crosslinking agent, antioxidant, flow dispersing agent, and coupling agent. After rolling 3 / 4 around 3 times, alternately add clay, talcum powder, white carbon black, and paraffin oil. After the feeding is completed, roll 3 / 4 around 3 times. S3 adds vulcanizing agent, and after the feeding is completed, adjusts the roller distance to 1mm, makes triangle packs 5-8 times, and adjusts the roller distance to 2mm to produce sheets to form a blend of EPDM rubber and cis-1,1-dimethylbutyl rubber.

10. The method for preparing the insulating adhesive resistant to high temperature extrusion deformation according to claim 9, characterized in that: The vulcanized rubber preparation parameters in step S3 are: a flat plate vulcanizer temperature of 170-200° C., a pressure of 10-15 MPa, a vulcanization time of 15-30 min, and a vulcanized sheet size of 140 mm×120 mm×1 mm.

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