Thermosetting insulating material for UL and CUL cables

Abstract

The invention relates to the technical field of cable insulating materials, and discloses a thermosetting insulating material for UL and CUL cables, which comprises the following components in parts by mass: 40-60 parts of ethylene propylene diene monomer, 200-300 parts of filler, 20-30 parts of epoxy resin, 10-40 parts of zinc borate, 2-10 parts of active agent, 1-10 parts of coloring agent, 0.5-5 parts of anti-aging agent and 1-5 parts of coupling agent A-1721. The thermosetting insulating material for UL and CUL cables has good flexibility, the dispersion uniformity of other materials is verified through numerous times of detection, the molecular structure is improved, the flexibility of the insulating material is better, the UL / CUL standard can be met, the tensile property, the brittleness temperature and the like of the cables in the low-temperature environment of-40 DEG C can be endured, and the thermosetting insulating material has high oil resistance and humidity and heat resistance, and can be widely applied to the field of cables. And meanwhile, the cable has obvious advantages in the aspects of low temperature resistance, cracking resistance, tensile resistance, corrosion resistance, ozone resistance and the like, meets the environmental protection requirement, and is suitable for occasions of special working environments with extremely low capacitance change rate or very high safety.

Description

Technical Field

[0001] The present invention relates to the technical field of cable insulation materials, in particular to a UL and CUL cable thermosetting insulation material. Background Art

[0002] In today's society, electricity is widely used and plays an important role in production and life. Cables, as carriers of electrical energy transmission and distribution, play a crucial role in modern society. As the power of electrical equipment in my country generally increases, the safety of power supply in residential, mining, petrochemical, and port areas has attracted the attention of relevant national departments, and the performance requirements for wires and cables have also increased accordingly. Few Chinese wire and cable companies have obtained UL and CUL certifications, because such cables can be used for both internal and external use, as well as in more important industrial applications.

[0003] However, the current UL standard uses thermosetting EPDM ethylene propylene rubber material as the insulation layer. However, EPDM itself is a non-polar rubber and is not resistant to mineral oil and fuel. It is severely swollen by such oils and fails. It has poor oil and moisture resistance and heat resistance, and has major defects.

[0004] In view of this, an in-depth study was conducted on the above-mentioned issues, and a UL and CUL cable thermosetting insulation material was proposed. Summary of the Invention

[0005] The object of the present invention is to provide a UL, CUL cable thermosetting insulation material to solve the problem of poor oil resistance and moisture and heat resistance of existing cable thermosetting insulation materials mentioned in the background art.

[0006] To achieve the above object, the present invention provides the following technical solution: a UL, CUL cable thermosetting insulation material, comprising, by mass: 40-60 parts of EPDM rubber, 200-300 parts of filler, 20-30 parts of epoxy resin, 10-40 parts of zinc borate, 2-10 parts of active agent, 1-10 parts of colorant, 0.5-5 parts of antioxidant, 1-5 parts of coupling agent A-172, 2-8 parts of peroxide crosslinking agent, 5-15 parts of processing aid, 1-4 parts of antioxidant and 5-12 parts of nanoparticles; The third monomer of the EPDM rubber is ethylidene norbornene; wherein the ethylene content is 55-70 wt %, and the Mooney viscosity of the EPDM rubber is 25-50 (ML (1+4), 125°C); The filler consists of calcined kaolin and ultrafine talc powder.

[0007] As is well known in the art, the EPDM rubber is a copolymer of ethylene, propylene and a non-conjugated diene. In the present invention, the third monomer, i.e., the non-conjugated diene, is ethylidene norbornene. Within the range of ethylene content, the Mooney viscosity can be controlled by controlling the content of propylene and ethylidene norbornene.

[0008] As a preferred technical solution of the present invention, the mass ratio of calcined kaolin and ultrafine talc in the filler is (1-5): (5:1).

[0009] As a preferred technical solution of the present invention, the epoxy resin has a molecular weight of 100,000 to 150,000. It is understood that the epoxy resin is a type of high-molecular-weight polymer containing two or more epoxy groups in the molecule, with a backbone structure of an aliphatic, alicyclic, or aromatic organic compound; examples include common bisphenol A epoxy resins (E51, E44, EPON828, EP4100).

[0010] As a preferred technical solution of the present invention, the active agent is composed of zinc oxide and stearic acid, and preferably the mass ratio of zinc oxide to stearic acid is 1: (0.01-0.1).

[0011] As a preferred technical solution of the present invention, the processing aid is a mixture of polyethylene wax and 2280 paraffin oil in any proportion.

[0012] It is understood that the peroxide crosslinking agent refers to a class of compounds containing a peroxy (OO) structure that can undergo free radical polymerization under high temperature conditions to form a crosslinked structure between polymer chains, such as BIBP.

[0013] As a preferred technical solution of the present invention, the antioxidant is selected from at least one of dialkyldiphenylamine and antioxidant 1010.

[0014] As a preferred technical solution of the present invention, the antioxidant is selected from at least one of antioxidant RD and antioxidant MB.

[0015] As a preferred technical solution of the present invention, the nanoparticles are inorganic compound nanoparticles, including oxides, hydroxides and salts, including but not limited to at least one of nano-silicon dioxide, nano-zinc oxide, nano-aluminum oxide, nano-magnesium hydroxide, nano-calcium carbonate, etc.

[0016] As a preferred technical solution of the present invention, the colorant is a colorant commonly used for cable materials, including but not limited to phthalocyanine blue, quinacridone red, titanium dioxide and other commonly used colorants.

[0017] Another object of the present invention is to provide a method for preparing the above-mentioned UL and CUL cable thermosetting insulation material, comprising the following steps: S1. The EPDM rubber is placed in an internal mixer for plasticization; S2. The filler is added to an internal mixer and mixed with EPDM rubber, followed by the epoxy resin, zinc borate, active agent, colorant, antioxidant, coupling agent, processing aid, antioxidant and nanoparticles are put into mixing; S3. After the mixture in step two is cooled, a peroxide crosslinking agent is added and mixed; S4. The mixture obtained in step 3 is extruded and granulated through a screw extruder, and cooled to obtain a UL, CUL cable thermosetting insulation material.

[0018] As a preferred technical solution of the present invention, in the step 1, the mixing temperature is controlled to be 120-150° C., and the mixing time is 40-50 min.

[0019] As a preferred technical solution of the present invention, in step 2, the filler and EPDM rubber are mixed at 85-95°C for 3-15 minutes before adding other components, and the mixing temperature is controlled at 100-110°C and the mixing time is 10-15 minutes.

[0020] As a preferred technical solution of the present invention, in step three, the mixing temperature is controlled to be 90-100° C., and the mixing time is 30-40 minutes.

[0021] As a preferred technical solution of the present invention, the temperature of the screw extruder in step 4 is 70-90° C., and the rotation speed is 150-200 r / min.

[0022] Compared with the prior art, the present invention has the following beneficial effects: The cable thermosetting insulation material provided by the present invention has good flexibility. The dispersion uniformity of other materials has been verified through numerous tests. The molecular structure is improved to make the insulation material more flexible. It can meet UL / CUL standards and can withstand the tensile performance and brittle temperature of the cable in a low temperature environment of -40°C. It has high oil resistance and moisture and heat resistance. At the same time, it has obvious advantages in low temperature resistance, crack resistance, tensile resistance, corrosion resistance, and ozone resistance. It also meets environmental protection requirements and is suitable for special working environments with extremely low capacitance change rate or high safety. In the present invention, the cable thermosetting insulation material is added with coupling agent A-172 to make the cable material have good water resistance and system compatibility, and improve physical properties; the addition of filler and zinc borate prevents the cable material from causing flame spread in a short time, greatly reduces the amount of smoke, and improves the oxygen index of the rubber compound, has excellent resistance to mineral oil and fuel oil, not only improves the electrical performance and safety performance of the cable, but also is a halogen-free and environmentally friendly material; the ethylene chain of EPDM rubber has greater mobility, which is beneficial to the glass transition of the copolymer, greatly improving the low-temperature performance and tear resistance It has good flexibility and plasticity, and the thermal stability of its saturated main chain has excellent heat-oxidation resistance; the addition of nanoparticles can effectively improve the tensile strength, and the surface effects such as the small size effect, quantum effect, unsaturated valence effect, and electron tunneling effect of the nanoparticles cause the increase in the interaction force between the rubber macromolecules, making the material have a significant reinforcement effect on the rubber, giving the rubber products wear resistance, tear resistance, heat resistance, cold resistance, tensile resistance and other properties, improving reliability and durability; adding it with epoxy resin as the base material can effectively improve the electrical insulation performance, and at the same time has the advantages of high strength, low shrinkage and corrosion resistance. DETAILED DESCRIPTION

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0024] Unless otherwise specified, all raw materials used in the examples are commercially available standards. Unless otherwise specified, all experimental methods used are methods well-known to those skilled in the art.

[0025] Example 1

[0026] A UL and CUL cable thermosetting insulation material comprises, by weight, 40 parts of EPDM rubber, 200 parts of a filler, 20 parts of an epoxy resin, 10 parts of zinc borate, 2 parts of an activator, 1 part of a colorant, 0.5 parts of an antioxidant RD, 1 part of a coupling agent A-172, 2 parts of a peroxide crosslinking agent, 5 parts of a processing aid, 1 part of an antioxidant, and 5 parts of magnesium hydroxide nanoparticles; The above components are specifically: The third monomer of EPDM rubber is ethylidene norbornene; wherein the ethylene content is 55wt% and the Mooney viscosity is 25 (ML(1+4), 125℃); The filler is made of calcined kaolin and ultrafine talc powder in a ratio of 1:1 by mass; The epoxy resin is bisphenol A epoxy resin E51 with a molecular weight of 100,000; The active agent is a mixture of zinc oxide and stearic acid in a mass ratio of 1:0.01; The processing aid is a mixture of polyethylene wax and 2280 paraffin oil in a mass ratio of 1:1; The peroxide crosslinker was BIBP, and the antioxidant was dialkyldiphenylamine; The method for preparing the above-mentioned UL and CUL cable thermosetting insulation material comprises the following steps: 1) Place the EPDM rubber in an internal mixer for plasticization; 2) Add the filler into the internal mixer and mix with the EPDM rubber, then add the epoxy resin, zinc borate, activator, colorant, antioxidant, coupling agent, processing aid, antioxidant and nanoparticles and mix; 3) After the mixture in step 2 is cooled, a peroxide crosslinking agent is added and mixed; 4) The mixture obtained in step 3 is extruded and granulated through a screw extruder, and cooled to obtain a UL, CUL cable thermosetting insulation material.

[0027] In step 1), the mixing temperature is controlled to be 120° C. and the mixing time is 50 min.

[0028] In step 2), the filler and EPDM rubber are mixed at 85° C. for 15 minutes, and then other components are added. The mixing temperature is controlled at 100° C. and the mixing time is 15 minutes.

[0029] In step 3), the mixing temperature is controlled to be 90° C. and the mixing time is 40 min.

[0030] In step 4), the temperature of the screw extruder is 70° C. and the rotation speed is 200 r / min.

[0031] Example 2

[0032] A UL and CUL cable thermosetting insulation material comprises, by weight, 50 parts of EPDM rubber, 250 parts of a filler, 25 parts of an epoxy resin, 25 parts of zinc borate, 6 parts of an activator, 5 parts of a colorant, 3 parts of an antioxidant MB, 23 parts of a coupling agent A-17, 4 parts of a peroxide crosslinking agent, 10 parts of a processing aid, 2 parts of an antioxidant, and 8 parts of silicon dioxide nanoparticles; The third monomer of the EPDM rubber is ethylidene norbornene, wherein the ethylene content is 65 wt % and the Mooney viscosity is 40 (ML (1+4), 125° C.); The filler is made of calcined kaolin and ultrafine talc powder in a mass ratio of 2:5; The epoxy resin is bisphenol A epoxy resin E44 with a molecular weight of 120,000; The active agent is a mixture of zinc oxide and stearic acid in a mass ratio of 1:0.05; The processing aid is a mixture of polyethylene wax and 2280 paraffin oil in a mass ratio of 3:2; The peroxide crosslinking agent was BIBP, and the antioxidant was antioxidant 1010.

[0033] The method for preparing the above-mentioned UL and CUL cable thermosetting insulation material comprises the following steps: 1) Place the EPDM rubber in an internal mixer for plasticization; 2) Add the filler into the internal mixer and mix with the EPDM rubber, then add the epoxy resin, zinc borate, activator, colorant, antioxidant, coupling agent, processing aid, antioxidant and nanoparticles and mix; 3) After the mixture in step 2 is cooled, a peroxide crosslinking agent is added and mixed; 4) The mixture obtained in step 3 is extruded and granulated through a screw extruder, and cooled to obtain a UL, CUL cable thermosetting insulation material.

[0034] In step 1), the mixing temperature is controlled to be 135° C. and the mixing time is 45 min.

[0035] In step 2), the filler and EPDM rubber are mixed at 90° C. for 10 minutes, and then other components are added. The mixing temperature is controlled at 105° C. and the mixing time is 13 minutes.

[0036] In step 3), the mixing temperature is controlled to be 95° C. and the mixing time is controlled to be 35 min.

[0037] In step 4), the temperature of the screw extruder is 80° C. and the rotation speed is 180 r / min.

[0038] Example 3

[0039] A UL and CUL cable thermosetting insulation material comprises, by weight, 60 parts of EPDM rubber, 300 parts of a filler, 30 parts of an epoxy resin, 40 parts of zinc borate, 10 parts of an activator, 10 parts of a colorant, 5 parts of an antioxidant RD, 5 parts of a coupling agent A-172, 8 parts of a peroxide crosslinking agent, 15 parts of a processing aid, 4 parts of an antioxidant, and 12 parts of aluminum oxide nanoparticles. The third monomer of EPDM rubber is ethylidene norbornene; wherein the ethylene content is 70wt% and the Mooney viscosity is 50 (ML (1+4), 125℃); The filler is made of calcined kaolin and ultrafine talc in a ratio of 5:2; The epoxy resin is bisphenol A epoxy resin EPON828, with a molecular weight of 150,000.

[0040] The active agent is a mixture of zinc oxide and stearic acid in a mass ratio of 1:0.03; The processing aid is a mixture of polyethylene wax and 2280 paraffin oil in a mass ratio of 2:3; The peroxide crosslinking agent is BIBP, and the antioxidant is dialkyldiphenylamine.

[0041] The method for preparing the above-mentioned UL and CUL cable thermosetting insulation material comprises the following steps: 1) Place the EPDM rubber in an internal mixer for plasticization; 2) Add the filler into the internal mixer and mix with the EPDM rubber, then add the epoxy resin, zinc borate, activator, colorant, antioxidant, coupling agent, processing aid, antioxidant and nanoparticles and mix; 3) After the mixture in step 2 is cooled, a peroxide crosslinking agent is added and mixed; 4) The mixture obtained in step 3 is extruded and granulated through a screw extruder, and cooled to obtain a UL, CUL cable thermosetting insulation material.

[0042] In step 1), the mixing temperature is controlled to be 150° C. and the mixing time is 40 min.

[0043] In step 2), the filler and EPDM rubber are mixed at 95° C. for 3 minutes, and then other components are added. The mixing temperature is controlled at 110° C. and the mixing time is 10 minutes.

[0044] In step 3), the mixing temperature is controlled to be 100° C. and the mixing time is 30 min.

[0045] In step 4), the temperature of the screw extruder is 90° C. and the rotation speed is 150 r / min.

[0046] Comparative Example 1

[0047] A thermosetting insulating material is provided, which differs from Example 1 in that the third monomer in the EPDM rubber is 1,4-hexadiene, and the other components, amounts, and conditions are the same. The preparation method is the same as that of Example 1.

[0048] Comparative Example 2

[0049] A thermosetting insulating material is different from Example 1 in that coupling agent A-172 is not used, and the other components and amounts are the same. The preparation method is the same as Example 1.

[0050] Comparative Example 3

[0051] A thermosetting insulating material is different from Example 1 in that epoxy resin is not added, and the other components and amounts are the same. The preparation method is the same as Example 1.

[0052] Test Example 1

[0053] The thermosetting insulating materials obtained in Examples 1-3 were respectively extruded into wires using a wire extruder, and then subjected to performance testing in accordance with UL 62-2018 (flexible wires and cables). The test results are shown in Table 1.

[0054] Table 1:

[0055] Test Example 2

[0056] Similar to Test Example 1, the thermosetting insulating materials obtained in Comparative Examples 1-3 were respectively made into wires by a wire extruder, and then subjected to main performance tests. The test results are shown in Table 2.

[0057] Table 2:

[0058] Note: “F” means that the inspection result does not meet the requirements.

[0059] It is not difficult to find from the above comparative examples 1-3 that, relative to Example 1, when the third monomer in the EPDM rubber is 1,4-hexadiene in comparative example 1, although the elongation at break is improved, the strength is significantly reduced, and in the aging test, the tensile strength retention rate and the elongation at break retention rate do not meet the requirements; when the coupling agent A-172 is not used in comparative example 2, the tensile strength and elongation at break are significantly reduced due to poor system compatibility; in addition, when the epoxy resin is not added in comparative example 3, the performance is also reduced due to the lack of epoxy resin crosslinking.

[0060] The contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0061] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A UL, CUL cable thermosetting insulation material, characterized in that: The composition comprises, by mass: 40-60 parts of EPDM rubber, 200-300 parts of filler, 20-30 parts of epoxy resin, 10-40 parts of zinc borate, 2-10 parts of active agent, 1-10 parts of colorant, 0.5-5 parts of antioxidant, 1-5 parts of coupling agent A-172, 2-8 parts of peroxide crosslinking agent, 5-15 parts of processing aid, 1-4 parts of antioxidant and 5-12 parts of nanoparticles; The third monomer of the EPDM rubber is ethylidene norbornene; wherein the ethylene content is 55-70 wt %, and the Mooney viscosity of the EPDM rubber is 25-50 (ML (1+4), 125°C); The filler consists of calcined kaolin and ultrafine talc powder.

2. The UL and CUL cable thermosetting insulation material according to claim 1, characterized in that: The molecular weight of the epoxy resin is 100,000 to 150,000.

3. The UL and CUL cable thermosetting insulation material according to claim 1, characterized in that: The active agent consists of zinc oxide and stearic acid in a mass ratio of 1: (0.01-0.1).

4. The UL and CUL cable thermosetting insulation material according to claim 1, characterized in that: The processing aid is a mixture of polyethylene wax and 2280 paraffin oil.

5. The UL and CUL cable thermosetting insulation material according to claim 1, characterized in that: The antioxidant is selected from at least one of dialkyldiphenylamine and antioxidant 1010.

6. The method for preparing a UL and CUL cable thermosetting insulation material according to claim 1, characterized in that: The following steps are involved: S1. The EPDM rubber is placed in an internal mixer for plasticization; S2. The filler is added to the internal mixer and mixed with EPDM rubber, followed by the epoxy resin, zinc borate, active agent, colorant, antioxidant, coupling agent, processing aid, antioxidant parts and nanoparticles are put into mixing; S3. After the mixture in step two is cooled, a peroxide crosslinking agent is added and mixed; S4. The mixture obtained in step 3 is extruded and granulated through a screw extruder, and cooled to obtain a UL, CUL cable thermosetting insulation material.

7. The method for preparing a UL or CUL cable thermosetting insulation material according to claim 6, characterized in that: In the step 1, the mixing temperature is controlled to be 120-150° C., and the mixing time is 40-50 min.

8. The method for preparing a UL and CUL cable thermosetting insulation material according to claim 6, characterized in that: In the step 2, the filler and EPDM rubber are mixed at 85-95° C. for 3-15 minutes, and then other components are added. The mixing temperature is controlled at 100-110° C. and the mixing time is 10-15 minutes.

9. The method for preparing a UL and CUL cable thermosetting insulation material according to claim 6, characterized in that: In the step 3, the mixing temperature is controlled to be 90-100° C., and the mixing time is 30-40 minutes.

10. The method for preparing a UL and CUL cable thermosetting insulation material according to claim 6, characterized in that: In the step 4, the temperature of the screw extruder is 70-90° C., and the rotation speed is 150-200 r / min.

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