Preparation process of high-temperature-resistant flame-retardant chloroprene rubber composite material

Abstract

The invention discloses a preparation process of a high-temperature-resistant flame-retardant chloroprene rubber composite material, and relates to the technical field of chloroprene rubber production. Wherein the raw materials comprise 80 to 100 parts of chloroprene rubber, 40 to 60 parts of magnesium hydroxide, 15 to 25 parts of decabromodiphenyl ethane, 6 to 10 parts of antimony trioxide, 4 to 6 parts of zinc oxide, 3 to 5 parts of magnesium oxide, 0.6 to 1 part of an accelerant NA-22, 1 to 2 parts of stearic acid, 0.8 to 1.5 parts of an anti-aging agent 4010NA, 0.8 to 1.5 parts of an anti-aging agent RD, 30 to 50 parts of carbon black N330, 8 to 15 parts of a plasticizer DOTP and 5 to 8 parts of a synergistic intermediate. Thermal oxidation degradation of a polymer chain is delayed through the synergistic anti-oxidation effect formed by adding the synergistic intermediate into the chloroprene rubber composite material raw material, and micronized wax migrates to the surface to form a physical barrier to effectively isolate oxygen, so that the requirements of high-temperature and high-reliability application scenes such as an automobile engine compartment and the like are met.

Description

Technical Field

[0001] This invention relates to the field of chloroprene rubber production technology, and more specifically, to a preparation process for a high-temperature resistant and flame-retardant chloroprene rubber composite material. Background Technology

[0002] Chloroprene rubber is widely used in the automotive, electronics, and chemical industries due to its excellent oil resistance, weather resistance, and mechanical properties. It is one of the key basic materials, especially in the seals and pipelines in the automotive engine compartment. However, the automotive engine compartment is a typical high-temperature, high-oxygen, and harsh service environment. It is under continuous high temperature for a long time, accompanied by mechanical vibration and oil and gas corrosion, which puts extremely high requirements on the heat aging resistance of chloroprene rubber composites. However, conventional chloroprene rubber composites currently on the market usually rely on single or simply compounded chemical antioxidants to resist thermo-oxidative aging. Although such antioxidant systems can delay material aging in the short term, the antioxidants are easily consumed rapidly under long-term high-temperature action, leading to severe thermo-oxidative degradation of the polymer chains, resulting in problems of low practicality and functionality. Summary of the Invention

[0003] In view of the problems in related technologies, this invention proposes a preparation process for high-temperature resistant and flame-retardant chloroprene rubber composite materials to overcome the above-mentioned technical problems existing in the existing related technologies.

[0004] Therefore, the specific technical solution adopted by the present invention is as follows: A high-temperature flame-retardant chloroprene rubber composite material comprises the following raw materials in parts by weight: 80-100 parts chloroprene rubber, 40-60 parts magnesium hydroxide, 15-25 parts decabromodiphenyl ethane, 6-10 parts antimony trioxide, 4-6 parts zinc oxide, 3-5 parts magnesium oxide, 0.6-1 part accelerator NA-22, 1-2 parts stearic acid, 0.8-1.5 parts antioxidant 4010NA, 0.8-1.5 parts antioxidant RD, 30-50 parts carbon black N330, 8-15 parts plasticizer DOTP, and 5-8 parts synergistic intermediates; The collaborative intermediate is made by the following steps: Step 1: Add antioxidant 445 and micronized wax to a high-speed mixer and mix to obtain a premix. Step 2: Slowly add the plasticizer DOTP while maintaining stirring in a high-speed mixer. Increase the speed and continue stirring to form a uniform paste-like pre-dispersion between the premix and the plasticizer DOTP, thus obtaining a synergistic intermediate.

[0005] In a preferred embodiment, the mass ratio of antioxidant 445 to micronized wax used in step 1 is 1:3, the stirring speed is 200-300 r / min, and the stirring time is 5 minutes.

[0006] In a preferred embodiment, the mass ratio of plasticizer DOTP to antioxidant 445 in step 2 is 8:1, the stirring speed is 800-1000 r / min, and the stirring time is 20-30 minutes.

[0007] A preparation process for a high-temperature resistant and flame-retardant chloroprene rubber composite material includes the following preparation steps: The preparation steps include the following: S1. Weigh the following raw materials by mass: the raw materials consist of 80-100 parts chloroprene rubber, 40-60 parts magnesium hydroxide, 15-25 parts decabromodiphenyl ethane, 6-10 parts antimony trioxide, 4-6 parts zinc oxide, 3-5 parts magnesium oxide, 0.6-1 parts accelerator NA-22, 1-2 parts stearic acid, 0.8-1.5 parts antioxidant 4010NA, 0.8-1.5 parts antioxidant RD, 30-50 parts carbon black N330, 8-15 parts plasticizer DOTP, and 5-8 parts synergistic intermediates; S2. Place magnesium hydroxide and antimony trioxide in an oven to dry to remove moisture. Put chloroprene rubber into a mixer for plasticizing. Then, add the synergistic intermediate, magnesium oxide, stearic acid, antioxidant 4010NA, and antioxidant RD in sequence and mix. After mixing, add carbon black N330, magnesium hydroxide, decabromodiphenyl ethane, antimony trioxide, and plasticizer DOTP. Mix until the temperature reaches 110-120℃ and then discharge the rubber to obtain the compound. S3. After cooling the rubber compound on a two-roll mill, roll it out in a triangular shape and let it cool for 4 hours. Then, roll the rubber compound through the two-roll mill to wrap the rollers. Then, add zinc oxide and accelerator NA-22 in sequence. Cut the rubber compound with left and right cutters and roll it in a triangular shape 5-8 times. After mixing evenly, adjust the roller gap and roll it out to obtain the final rubber compound. S4. Place the final rubber compound into the mold of the flat vulcanizing machine for vulcanization molding. Place the vulcanized product into the blower oven for secondary vulcanization for 4 hours. After cooling in the oven, take it out to obtain high temperature resistant flame retardant chloroprene rubber composite material.

[0008] In a preferred embodiment, the drying temperature of magnesium hydroxide and antimony trioxide in S2 in the oven is 100-110°C, the drying time is 2 hours, and the mixing time of the synergistic intermediate, magnesium oxide, stearic acid, antioxidant 4010NA and antioxidant RD is 2 minutes.

[0009] In a preferred embodiment, the temperature of the thin-walled heat dissipation cooling in S3 is cooled to 50°C, and the parameters of the mixing rubber roll open mill are set as roll temperature 40±5°C and roll gap 1.0-1.5mm.

[0010] In a preferred embodiment, after the mixture is homogeneously mixed in step S3, the roller gap is increased to produce sheets, wherein the roller gap is increased to 2.0-3.0 mm.

[0011] In a preferred embodiment, the vulcanizing temperature of the flat vulcanizing machine in step S4 is 160±2℃, the vulcanizing pressure is 12-15MPa, and the vulcanizing time is based on the T90 value measured by the vulcanizer plus 2 minutes for vulcanization molding.

[0012] In a preferred embodiment, the temperature of the second-stage vulcanization in S4 is 150±2℃.

[0013] The beneficial effects of this invention are as follows: 1. This invention adds a synergistic intermediate to the raw material of chloroprene rubber composite material. The antioxidant 445 therein forms a synergistic antioxidant effect with the antioxidants 4010NA and RD in the basic formula, which delays the thermo-oxidative degradation of the polymer chain. At the same time, the micronized wax migrates to the surface to form a physical barrier, effectively isolating oxygen and improving the long-term heat aging resistance of chloroprene rubber composite material, so that it can better meet the requirements of high temperature and high reliability application scenarios such as automotive engine compartment. 2. This invention effectively isolates oxygen and heat from intrusion by migrating micronized wax in the intermediate to the material surface to form a dense physical barrier layer. At the same time, it forms a "physical + chemical" dual protection mechanism with the internal chemical anti-aging system, which synergistically reduces the consumption rate of anti-aging agents and extends the service life of materials in high-temperature environments. 3. The synergistic intermediate of this invention uses DOTP as a carrier and is perfectly integrated with the whole system. Through high shear, the antioxidant 445, micronized wax and other solid functional additives are dispersed into a fine and uniform paste to form a pre-dispersed masterbatch to improve the uniformity of subsequent distribution, avoid performance shortcomings caused by poor local dispersion, and enhance the material processing stability and performance consistency. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a flowchart of a preparation process for a high-temperature resistant and flame-retardant chloroprene rubber composite material according to an embodiment of the present invention. Detailed Implementation

[0016] To further illustrate the various embodiments, the present invention provides accompanying drawings, which are part of the disclosure of the present invention. These drawings are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these drawings, those skilled in the art should be able to understand other possible implementation methods and the advantages of the present invention. The components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0017] According to an embodiment of the present invention, a preparation process for a high-temperature resistant and flame-retardant chloroprene rubber composite material is provided.

[0018] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments: Example 1: A high-temperature resistant and flame-retardant chloroprene rubber composite material according to an embodiment of the present invention comprises the following raw materials in parts by weight: wherein the raw materials consist of 80-100 parts chloroprene rubber, 40-60 parts magnesium hydroxide, 15-25 parts decabromodiphenyl ethane, 6-10 parts antimony trioxide, 4-6 parts zinc oxide, 3-5 parts magnesium oxide, 0.6-1 part accelerator NA-22, 1-2 parts stearic acid, 0.8-1.5 parts antioxidant 4010NA, 0.8-1.5 parts antioxidant RD, 30-50 parts carbon black N330, 8-15 parts plasticizer DOTP, and 5-8 parts synergistic intermediates; A method for preparing a high-temperature resistant and flame-retardant chloroprene rubber composite material includes the following preparation steps: The first step is to weigh the following raw materials according to their mass percentages: the raw materials consist of 80-100 parts chloroprene rubber, 40-60 parts magnesium hydroxide, 15-25 parts decabromodiphenyl ethane, 6-10 parts antimony trioxide, 4-6 parts zinc oxide, 3-5 parts magnesium oxide, 0.6-1 parts accelerator NA-22, 1-2 parts stearic acid, 0.8-1.5 parts antioxidant 4010NA, 0.8-1.5 parts antioxidant RD, 30-50 parts carbon black N330, 8-15 parts plasticizer DOTP, and 5-8 parts synergistic intermediates; Step 2: Place magnesium hydroxide and antimony trioxide in an oven and dry at 100-110℃ for 2 hours to remove moisture. Put chloroprene rubber into a mixer and plasticize for 30-60 seconds. Then add the synergistic intermediate, magnesium oxide, stearic acid, antioxidant 4010NA, and antioxidant RD in sequence and mix for 2 minutes. Then add carbon black N330, magnesium hydroxide, decabromodiphenyl ethane, antimony trioxide, and plasticizer DOTP and mix until the temperature reaches 110-120℃. Then discharge the rubber to obtain the compound. The third step is to heat the rubber compound on a two-roll mill and cool it to 50°C. Then, make triangular wraps to form sheets and let it cool for 4 hours. After that, set the roller temperature to 40±5°C and the roller gap to 1.0-1.5mm so that the rubber compound wraps around the roller. Then, add zinc oxide and accelerator NA-22 in sequence, cut with left and right cutters, and make triangular wraps 5-8 times. After mixing evenly, increase the roller gap to 2.0-3.0mm and sheet the final rubber compound. Step 4: Place the final compounded rubber into the mold of the flat vulcanizing machine, set the vulcanizing temperature of the flat vulcanizing machine to 160±2℃, the vulcanizing pressure to 12-15MPa, and the vulcanizing time to be based on the T90 value measured by the vulcanizer plus 2 minutes for vulcanization molding. Place the vulcanized product into a forced-air drying oven and perform secondary vulcanization at 150±2℃ for 4 hours. After cooling in the oven, remove the product to obtain a high-temperature resistant and flame-retardant chloroprene rubber composite material.

[0019] The collaborative intermediate is made by the following steps: Step 1: Add antioxidant 445 and micronized wax to a high-speed mixer and mix at 200-300 rpm for 5 minutes to obtain a premix. Step 2: While stirring in a high-speed mixer, slowly add the plasticizer DOTP, increase the speed to 800-1000 r / min, and stir for 20-30 minutes to form a uniform paste-like pre-dispersion between the premix and the plasticizer DOTP, thus obtaining a synergistic intermediate. The mass ratio of antioxidant 445 to micronized wax used is 1:3, and the mass ratio of plasticizer DOTP to antioxidant 445 is 8:1. The micronized wax is micronized polyethylene wax with a particle size D50 of 8.0µm.

[0020] Example 2: A high-temperature resistant and flame-retardant chloroprene rubber composite material, the specific process and preparation flow are as follows: The first step is to weigh the following raw materials according to the following mass percentages: the raw materials consist of 80 parts chloroprene rubber, 40 parts magnesium hydroxide, 15 parts decabromodiphenyl ethane, 6 parts antimony trioxide, 4 parts zinc oxide, 3 parts magnesium oxide, 0.6 parts accelerator NA-22, 1 part stearic acid, 0.8 parts antioxidant 4010NA, 0.8 parts antioxidant RD, 30 parts carbon black N330, 8 parts plasticizer DOTP, and 5 parts synergistic intermediates; Step 2: Place 40 parts magnesium hydroxide and 6 parts antimony trioxide in an oven and dry at 110°C for 2 hours to remove moisture. Put 80 parts chloroprene rubber into a mixer and plasticize for 45 seconds. Then add 5 parts synergistic intermediate, 3 parts magnesium oxide, 1 part stearic acid, 0.8 parts antioxidant 4010NA, and 0.8 parts antioxidant RD in sequence and mix for 2 minutes. Then add 30 parts carbon black N330, 40 parts magnesium hydroxide, 15 parts decabromodiphenyl ethane, 6 parts antimony trioxide, and 8 parts plasticizer DOTP and mix until the temperature reaches 110°C. Then discharge the rubber to obtain the compound. The third step is to heat the rubber compound on a two-roll mill and cool it to 50°C. Then, make triangular wraps to form sheets and let it cool for 4 hours. After that, set the roller temperature to 45°C and the roller gap to 1.0 mm so that the rubber compound wraps around the roller. Then, add 4 parts of zinc oxide and 0.6 parts of accelerator NA-22 in sequence. Cut the rubber compound with left and right cutters and make triangular wraps 8 times. After mixing evenly, increase the roller gap to 2.5 mm and sheet the rubber compound to obtain the final rubber compound. Step 4: Place the final compounded rubber into the mold of the flat vulcanizing machine, set the vulcanizing temperature of the flat vulcanizing machine to 160℃, the vulcanizing pressure to 15MPa, and the vulcanizing time to be based on the T90 value measured by the vulcanizer plus 2 minutes for vulcanization molding. Place the vulcanized product into a forced-air drying oven and perform secondary vulcanization at 150℃ for 4 hours. After cooling in the oven, remove the product to obtain a high-temperature resistant and flame-retardant chloroprene rubber composite material.

[0021] The collaborative intermediate is made by the following steps: Step 1: Add antioxidant 445 and micronized wax to a high-speed mixer and stir at 250 r / min for 5 minutes to obtain a premix, wherein the mass ratio of antioxidant 445 to micronized wax is 1:3. Step 2: Slowly add plasticizer DOTP while maintaining stirring in a high-speed mixer, increase the speed to 1000 r / min and stir for 30 minutes to form a uniform paste-like pre-dispersion between the premix and plasticizer DOTP, thus obtaining a synergistic intermediate. The mass ratio of plasticizer DOTP to antioxidant 445 is 8:1, and the micronized wax is micronized polyethylene wax with a particle size D50 of 8.0 µm.

[0022] Example 3: A high-temperature resistant and flame-retardant chloroprene rubber composite material, the specific process and preparation flow are as follows: The first step is to weigh the following raw materials according to the following mass percentages: the raw materials consist of 100 parts chloroprene rubber, 60 parts magnesium hydroxide, 25 parts decabromodiphenyl ethane, 10 parts antimony trioxide, 6 parts zinc oxide, 5 parts magnesium oxide, 1 part accelerator NA-22, 2 parts stearic acid, 1.5 parts antioxidant 4010NA, 1.5 parts antioxidant RD, 50 parts carbon black N330, 15 parts plasticizer DOTP, and 8 parts synergistic intermediates; Step 2: Place 60 parts magnesium hydroxide and 10 parts antimony trioxide in an oven and dry at 110°C for 2 hours to remove moisture. Put 100 parts chloroprene rubber into a mixer and plasticize for 45 seconds. Then add 8 parts synergistic intermediate, 5 parts magnesium oxide, 2 parts stearic acid, 1.5 parts antioxidant 4010NA, and 1.5 parts antioxidant RD in sequence and mix for 2 minutes. Then add 50 parts carbon black N330, 60 parts magnesium hydroxide, 25 parts decabromodiphenyl ethane, 10 parts antimony trioxide, and 15 parts plasticizer DOTP and mix until the temperature reaches 110°C. Then discharge the rubber to obtain the compound. The third step is to heat the rubber compound on a two-roll mill and cool it to 50°C. Then, make triangular wraps to form sheets and let it cool for 4 hours. After that, set the roller temperature to 45°C and the roller gap to 1.0 mm so that the rubber compound wraps around the roller. Then, add 6 parts of zinc oxide and 1 part of accelerator NA-22 in sequence. Cut the rubber compound with left and right cutters and make triangular wraps 8 times. After mixing evenly, increase the roller gap to 2.5 mm and sheet the rubber compound to obtain the final rubber compound. Step 4: Place the final compounded rubber into the mold of the flat vulcanizing machine, set the vulcanizing temperature of the flat vulcanizing machine to 160℃, the vulcanizing pressure to 15MPa, and the vulcanizing time to be based on the T90 value measured by the vulcanizer plus 2 minutes for vulcanization molding. Place the vulcanized product into a forced-air drying oven and perform secondary vulcanization at 150℃ for 4 hours. After cooling in the oven, remove the product to obtain a high-temperature resistant and flame-retardant chloroprene rubber composite material.

[0023] The collaborative intermediate is made by the following steps: Step 1: Add antioxidant 445 and micronized wax to a high-speed mixer and stir at 250 r / min for 5 minutes to obtain a premix, wherein the mass ratio of antioxidant 445 to micronized wax is 1:3. Step 2: Slowly add plasticizer DOTP while maintaining stirring in a high-speed mixer, increase the speed to 1000 r / min and stir for 30 minutes to form a uniform paste-like pre-dispersion between the premix and plasticizer DOTP, thus obtaining a synergistic intermediate. The mass ratio of plasticizer DOTP to antioxidant 445 is 8:1, and the micronized wax is micronized polyethylene wax with a particle size D50 of 8.0 µm.

[0024] Comparative Example 1: By removing the synergistic intermediate from Example 2, a high-temperature resistant and flame-retardant chloroprene rubber composite material was prepared according to the following steps: A high-temperature resistant and flame-retardant chloroprene rubber composite material, the specific process and preparation flow are as follows: The first step is to weigh the following raw materials according to their mass percentages: 80 parts chloroprene rubber, 40 parts magnesium hydroxide, 15 parts decabromodiphenyl ethane, 6 parts antimony trioxide, 4 parts zinc oxide, 3 parts magnesium oxide, 0.6 parts accelerator NA-22, 1 part stearic acid, 0.8 parts antioxidant 4010NA, 0.8 parts antioxidant RD, 30 parts carbon black N330, and 8 parts plasticizer DOTP; Step 2: Place 40 parts magnesium hydroxide and 6 parts antimony trioxide in an oven and dry at 110°C for 2 hours to remove moisture. Put 80 parts chloroprene rubber into a mixer and plasticize for 45 seconds. Then add 3 parts magnesium oxide, 1 part stearic acid, 0.8 parts antioxidant 4010NA, and 0.8 parts antioxidant RD in sequence and mix for 2 minutes. Then add 30 parts carbon black N330, 40 parts magnesium hydroxide, 15 parts decabromodiphenyl ethane, 6 parts antimony trioxide, and 8 parts plasticizer DOTP and mix until the temperature reaches 110°C. Then discharge the rubber to obtain the compound. The third step is to heat the rubber compound on a two-roll mill and cool it to 50°C. Then, make triangular wraps to form sheets and let it cool for 4 hours. After that, set the roller temperature to 45°C and the roller gap to 1.0 mm so that the rubber compound wraps around the roller. Then, add 4 parts of zinc oxide and 0.6 parts of accelerator NA-22 in sequence. Cut the rubber compound with left and right cutters and make triangular wraps 8 times. After mixing evenly, increase the roller gap to 2.5 mm and sheet the rubber compound to obtain the final rubber compound. Step 4: Place the final rubber compound into the mold of the flat vulcanizing machine, set the vulcanizing temperature of the flat vulcanizing machine to 160℃, the vulcanizing pressure to 15MPa, and the vulcanizing time to be based on the T90 value measured by the vulcanizer + 2 minutes for vulcanization molding. Place the vulcanized product into a forced-air drying oven and perform secondary vulcanization at 150℃ for 4 hours. After cooling in the oven, take it out to obtain a high-temperature resistant flame-retardant chloroprene rubber composite material. Comparative Example 2: The synergistic intermediate in Example 3 was removed, and the high-temperature flame-retardant chloroprene rubber composite material was prepared according to the following steps: The first step is to weigh the following raw materials according to their mass percentages: 100 parts chloroprene rubber, 60 parts magnesium hydroxide, 25 parts decabromodiphenyl ethane, 10 parts antimony trioxide, 6 parts zinc oxide, 5 parts magnesium oxide, 1 part accelerator NA-22, 2 parts stearic acid, 1.5 parts antioxidant 4010NA, 1.5 parts antioxidant RD, 50 parts carbon black N330, and 15 parts plasticizer DOTP; Step 2: Place 60 parts magnesium hydroxide and 10 parts antimony trioxide in an oven and dry at 110°C for 2 hours to remove moisture. Put 100 parts chloroprene rubber into a mixer and plasticize for 45 seconds. Then add 5 parts magnesium oxide, 2 parts stearic acid, 1.5 parts antioxidant 4010NA, and 1.5 parts antioxidant RD in sequence and mix for 2 minutes. Then add 50 parts carbon black N330, 60 parts magnesium hydroxide, 25 parts decabromodiphenyl ethane, 10 parts antimony trioxide, and 15 parts plasticizer DOTP and mix until the temperature reaches 110°C. Then discharge the rubber to obtain the compound. The third step is to heat the rubber compound on a two-roll mill and cool it to 50°C. Then, make triangular wraps to form sheets and let it cool for 4 hours. After that, set the roller temperature to 45°C and the roller gap to 1.0 mm so that the rubber compound wraps around the roller. Then, add 6 parts of zinc oxide and 1 part of accelerator NA-22 in sequence. Cut the rubber compound with left and right cutters and make triangular wraps 8 times. After mixing evenly, increase the roller gap to 2.5 mm and sheet the rubber compound to obtain the final rubber compound. Step 4: Place the final rubber compound into the mold of the flat vulcanizing machine, set the vulcanizing temperature of the flat vulcanizing machine to 160℃, the vulcanizing pressure to 15MPa, and the vulcanizing time to be based on the T90 value measured by the vulcanizer + 2 minutes for vulcanization molding. Place the vulcanized product into a forced-air drying oven and perform secondary vulcanization at 150℃ for 4 hours. After cooling in the oven, take it out to obtain a high-temperature resistant flame-retardant chloroprene rubber composite material. Experimental Example 1: The high-temperature flame-retardant neoprene rubber composites obtained in Examples 2 and 3 and Comparative Examples 1 and 2 were subjected to performance tests, including tensile strength and elongation at break tests, hardness tests, hot air aging tests, and vertical ignition rating tests. The test results are shown in Tables 1 and 2. Table 1: Initial Physical and Mechanical Properties and Flame Retardancy Test Table For the tensile strength and elongation at break tests, the vulcanized rubber compounds obtained in Comparative Examples 1 and 2, as well as Examples 2 and 3, were cut into dumbbell-shaped specimens using a standard cutter. The specimens were clamped in the upper and lower clamps of a universal testing machine and stretched at a uniform speed of 500 mm / min until they broke. The maximum force value and the length change rate at break were recorded. Five specimens were tested for each formulation and the average value was taken. The hardness test was performed by stacking the vulcanized rubber sheets obtained in Comparative Examples 1 and 2 and Examples 2 and 3 into a flat test piece with a thickness of 6 mm. The indenter was pressed vertically and quickly onto the surface of the sample using a Shore A hardness tester. After the pointer stabilized, the scale value was read to obtain the Shore A hardness. The test was performed 5 times at different positions on the sample surface and the average value was taken. The oxygen index test involved preparing strip-shaped samples with dimensions of 100mm × 6.5mm × 3mm from the rubber compounds obtained in Comparative Examples 1 and 2, as well as Examples 2 and 3. The samples were vertically fixed in a combustion chamber, and a nitrogen + oxygen mixture was introduced into the chamber with an upward flow. The top of the sample was attempted to be ignited starting from an oxygen concentration of 25%, and its combustion behavior was observed. The oxygen concentration was adjusted using the "lifting method" based on whether the sample continued to burn for more than 3 minutes or the burning length exceeded 50mm. The lowest oxygen concentration percentage was calculated to obtain the limiting oxygen index (LOI). Five samples were tested for each formulation, and the average value was taken. The vertical burning test involved preparing strip-shaped samples with dimensions of 125mm × 13mm × 3mm from the rubber compounds obtained in Comparative Examples 1 and 2, as well as Examples 2 and 3. The lower end of the sample was burned with a Bunsen burner flame for 10 seconds. After removing the flame, the flaming burning time of the sample was recorded. If the sample extinguished, it was burned again for 10 seconds. The flaming burning time and the non-flaming burning time were recorded again after removing the flame. The grade was determined based on the sum of the two flaming burning times and whether the degreased cotton was ignited. Table 1 shows that, compared with the unadded Comparative Examples 1 and 2, Examples 2 and 3 with the addition of the synergistic intermediate showed a slight increase in initial tensile strength, elongation, and hardness, but this increase was not significant. This indicates that the main function of the synergistic intermediate was not to significantly improve the initial strength, but rather to act as a functional additive. In terms of flame retardant performance, the oxygen index (LOI) of the examples was about 3 percentage points higher than that of the comparative examples, and the vertical burning rating was improved from V-1 to V-0. This suggests that the micronized wax in the synergistic intermediate may have promoted the formation of a denser char layer during combustion, producing a synergistic effect with the main flame retardant system and further improving the flame retardant efficiency.

[0025] Table 2: Thermal Aging Performance Test Table The hot air aging test involved preparing the initial samples for tensile strength and hardness testing obtained from Comparative Examples 1 and 2, as well as Examples 2 and 3, and measuring the initial values. The samples were then suspended in a preheated oven at 150°C for 72 hours. After removal, the samples were cooled at standard laboratory temperature for 16 hours. The tensile strength, elongation at break, and hardness of the samples were measured again. The performance change rate was calculated by (post-aging value - pre-aging value) / pre-aging value × 100%.

[0026] Table 2 shows that Comparative Examples 1 and 2 exhibited severely degraded performance, with tensile strength decreasing by over 20% and elongation plummeting by 30%, becoming harder and more brittle. This indicates that the materials have aged and lost their usability under prolonged high temperatures. Examples 2 and 3, on the other hand, maintained good performance, with tensile strength decreasing by approximately 8%, elongation decreasing by approximately 16%, and hardness slightly increasing. The antioxidant 445 in the synergistic intermediate, together with antioxidants 4010NA and RD in the base formulation, formed a synergistic antioxidant effect, delaying the thermo-oxidative degradation of the polymer chains. Simultaneously, the physical barrier formed by the migration of micronized wax to the surface effectively isolated oxygen, thus constituting a dual chemical and physical protection, enhancing the material's performance. It has a long service life with high temperature resistance. After the antioxidant captures a free radical, it becomes a less active free radical. At this time, another antioxidant can react with this less active antioxidant free radical, regenerating it and restoring it to its active form, thus continuing to play a role and extending the effective life of the antioxidant system. Through the decomposition of hydrogen peroxide by RD, 445 and 4010NA synergistically terminate the growth of free radical chains, forming a three-dimensional, multi-layered chemical protection system that synergistically resists thermo-oxidative aging. After vulcanization, the micronized wax gradually migrates to the surface of the rubber product, forming a dense and continuous protective film to isolate oxygen and block the impact of heat.

[0027] In summary, this invention adds a synergistic intermediate to the chloroprene rubber composite material raw material. The antioxidant 445 therein forms a strong synergistic antioxidant effect with the antioxidants 4010NA and RD in the basic formulation, which delays the thermo-oxidative degradation of the polymer chain. At the same time, the micronized wax migrates to the surface to form a physical barrier, effectively isolating oxygen and improving the long-term heat aging resistance of the chloroprene rubber composite material, so that it can better meet the requirements of high-temperature and high-reliability application scenarios such as automotive engine compartments. By migrating the micronized wax in the synergistic intermediate to the material surface to form a dense physical barrier layer, it effectively isolates oxygen and heat from intrusion. At the same time, it forms a "physical + chemical" dual protection mechanism with the internal chemical anti-aging system, synergistically reducing the consumption rate of anti-aging agents and extending the service life of materials in high-temperature environments.

[0028] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-temperature resistant, flame-retardant chloroprene rubber composite material, characterized in that, The raw materials include the following parts by weight: 80-100 parts chloroprene rubber, 40-60 parts magnesium hydroxide, 15-25 parts decabromodiphenyl ethane, 6-10 parts antimony trioxide, 4-6 parts zinc oxide, 3-5 parts magnesium oxide, 0.6-1 part accelerator NA-22, 1-2 parts stearic acid, 0.8-1.5 parts antioxidant 4010NA, 0.8-1.5 parts antioxidant RD, 30-50 parts carbon black N330, 8-15 parts plasticizer DOTP, and 5-8 parts synergistic intermediates; The collaborative intermediate is made by the following steps: Step 1: Add antioxidant 445 and micronized wax in a mass ratio of 1:3 into a high-speed mixer and mix to obtain a premix. Step 2: Slowly add plasticizer DOTP while maintaining stirring in a high-speed mixer. Increase the speed and continue stirring to form a uniform paste-like pre-dispersion between the premix and plasticizer DOTP, thus obtaining a synergistic intermediate. The mass ratio of plasticizer DOTP to antioxidant 445 is 8:

1.

2. The high-temperature resistant and flame-retardant chloroprene rubber composite material according to claim 1, characterized in that, The antioxidant 445 and the micronized wax used in step 1 are mixed at a speed of 200-300 r / min for 5 minutes.

3. The high-temperature resistant and flame-retardant chloroprene rubber composite material according to claim 1, characterized in that, In step 2, the stirring speed is 800-1000 r / min and the stirring time is 20-30 minutes.

4. A preparation process for a high-temperature resistant, flame-retardant chloroprene rubber composite material as described in any one of claims 1-3, characterized in that, The preparation steps include the following: S1. Weigh the following raw materials by mass: the raw materials consist of 80-100 parts chloroprene rubber, 40-60 parts magnesium hydroxide, 15-25 parts decabromodiphenyl ethane, 6-10 parts antimony trioxide, 4-6 parts zinc oxide, 3-5 parts magnesium oxide, 0.6-1 parts accelerator NA-22, 1-2 parts stearic acid, 0.8-1.5 parts antioxidant 4010NA, 0.8-1.5 parts antioxidant RD, 30-50 parts carbon black N330, 8-15 parts plasticizer DOTP, and 5-8 parts synergistic intermediates; S2. Place magnesium hydroxide and antimony trioxide in an oven to dry to remove moisture. Put chloroprene rubber into a mixer for plasticizing. Then, add the synergistic intermediate, magnesium oxide, stearic acid, antioxidant 4010NA, and antioxidant RD in sequence and mix. After mixing, add carbon black N330, magnesium hydroxide, decabromodiphenyl ethane, antimony trioxide, and plasticizer DOTP. Mix until the temperature reaches 110-120℃ and then discharge the rubber to obtain the compound. S3. After cooling the rubber compound on a two-roll mill, roll it out in a triangular shape and let it cool for 4 hours. Then, roll the rubber compound through the two-roll mill to wrap the rollers. Then, add zinc oxide and accelerator NA-22 in sequence. Cut the rubber compound with left and right cutters and roll it in a triangular shape 5-8 times. After mixing evenly, adjust the roller gap and roll it out to obtain the final rubber compound. S4. Place the final rubber compound into the mold of the flat vulcanizing machine for vulcanization molding. Place the vulcanized product into the blower oven for secondary vulcanization for 4 hours. After cooling in the oven, take it out to obtain high temperature resistant flame retardant chloroprene rubber composite material.

5. The preparation process of a high-temperature resistant flame-retardant chloroprene rubber composite material according to claim 4, characterized in that, In S2, the drying temperature of magnesium hydroxide and antimony trioxide in the oven is 100-110℃, and the drying time is 2 hours. The mixing time of the synergistic intermediate, magnesium oxide, stearic acid, antioxidant 4010NA, and antioxidant RD is 2 minutes.

6. The preparation process of a high-temperature resistant flame-retardant chloroprene rubber composite material according to claim 4, characterized in that, The temperature of the thin-walled heat dissipation cooling in S3 is 50℃, and the parameters of the mixing rubber roll open mill are set as roll temperature 40±5℃ and roll gap 1.0-1.5mm.

7. The preparation process of a high-temperature resistant flame-retardant chloroprene rubber composite material according to claim 4, characterized in that, After the mixture in step S3 is homogenized, the roller gap is increased to produce the sheet, wherein the roller gap is increased to 2.0-3.0 mm.

8. The preparation process of a high-temperature resistant flame-retardant chloroprene rubber composite material according to claim 4, characterized in that, The S4 flat vulcanizing machine has a vulcanization temperature of 160±2℃, a vulcanization pressure of 12-15MPa, and a vulcanization time of 2 minutes based on the T90 value measured by the vulcanizer.

9. The preparation process of a high-temperature resistant flame-retardant chloroprene rubber composite material according to claim 4, characterized in that, The temperature for the second stage of vulcanization in S4 is 150±2℃.

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