A rubber composition having flame retardant functionality and process for its production
By utilizing the cross-linked structure of aerogel-type flame retardant and smoke suppressant, the problems of flammability and toxic fumes from natural rubber are solved, achieving highly efficient flame retardancy and low smoke release, thus avoiding the shortcomings of traditional flame retardants.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- 云浮市骏驰新材料科技有限公司
- Filing Date
- 2024-11-27
- Publication Date
- 2026-05-29
Smart Images
Figure CN122103704A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of rubber technology, and more specifically to a rubber composition with flame-retardant properties and its production process. Background Technology
[0002] Against the backdrop of rapid development in modern industry and technology, rubber materials, due to their unique elasticity and wear resistance, are widely used in various fields such as automobile manufacturing, aerospace, wire and cable, and building materials. Among the many rubber matrices, natural rubber has high mechanical strength, strong resistance to flexural fatigue, and excellent cold resistance, thus showing great application potential in tire manufacturing, rubber products, and medical devices. However, since natural rubber is mainly polymerized from isoprene monomers, its molecular chain contains a large number of carbon-hydrogen bonds and lacks flame-retardant elements, making it highly flammable. Moreover, natural rubber materials produce a large amount of toxic fumes during combustion, posing a serious threat to life and property safety. Therefore, the development of natural rubber compositions with higher flame-retardant properties, lower smoke density, and lower toxicity has become a research hotspot.
[0003] Currently, flame retardants are commonly used to improve the flame retardant properties of natural rubber, with halogenated, phosphorus-based, and inorganic flame retardants being the most common. However, halogenated flame retardants produce toxic hydrogen halide gas during combustion, posing a threat to the environment and human health, thus limiting their application. Phosphorus-based flame retardants are often small-molecule types, easily volatilizing and dissipating during storage, making it difficult to guarantee the flame retardant durability of natural rubber. Inorganic flame retardants have poor flame retardant effects, usually requiring larger amounts to significantly improve the material's flame retardant properties; however, excessive amounts can negatively impact the material's mechanical properties, also presenting drawbacks in practical applications. Therefore, this invention provides a rubber composition with flame-retardant functionality, addressing the problems existing in the prior art. Summary of the Invention
[0004] (a) Technical problems to be solved
[0005] To address the shortcomings of existing technologies, this invention provides a rubber composition with flame-retardant properties and its production process.
[0006] (II) Technical Solution
[0007] A process for producing a flame-retardant rubber composition, wherein the rubber composition comprises the following raw materials measured in parts by weight:
[0008]
[0009] The production process includes the following steps;
[0010] The first step is to weigh and prepare all the raw materials according to the weight proportions. Then, place the natural rubber on the open mill for plasticization, and then add the polybutadiene rubber and knead it to form a rubber compound.
[0011] The second step is to add the rubber compound, flame retardant and smoke suppressant, filler, antioxidant, zinc oxide, accelerator and microcrystalline wax into the internal mixer, control the temperature at 100-120℃, the rotor speed at 30-50rpm, and mix for 1-2 minutes.
[0012] Third step: Continue to add the vulcanizing agent to the internal mixer, control the temperature at 90-100℃, continue mixing for 1-2 minutes, then transfer it to the vulcanizing agent, control the vulcanization temperature at 150-160℃, the rotation speed at 40-50 rpm, vulcanize for 30-40 minutes under a pressure of 10-15 MPa, then discharge the material and let it stand for 8-12 hours.
[0013] As a further aspect of the present invention, the specific preparation method of the flame-retardant and smoke-suppressing agent is as follows:
[0014] Xylooligosaccharides are added to an ethanol aqueous solution with a volume fraction of 60-70% and mechanically stirred until homogeneous to form a mixture. Then, the linker and phase transfer catalyst are added to the mixture. After the addition is complete, nitrogen gas is introduced for protection, and the temperature is raised to 70-80℃. After heat treatment for 8-12 hours, the nitrogen gas is removed and heating is stopped. After the material cools down, it is poured into a mold and allowed to stand to form. Then, the formed material is transferred to a freeze dryer and freeze-dried at a temperature of -40-50℃ for 24-48 hours to obtain the flame retardant and smoke suppressant preparation.
[0015] As a further aspect of the present invention, the specific preparation method of the connector includes the following steps:
[0016] Step 1: Add 1,4-bis(2-hydroxyethyl)piperazine and toluene to a nitrogen-filled polymerization reactor and stir until homogeneous. Then add an alkaline hydroxide aqueous solution. After the addition is complete, control the temperature at 50-60℃ and mechanically stir for 1-3 hours. Continue to add 2,3-dibromopropionic acid to the polymerization reactor and raise the temperature to 70-80℃. Keep the temperature and stir for 12-18 hours to obtain a nitrogen-containing intermediate.
[0017] Step 2: Add the nitrogen-containing intermediate, the active phosphorus-containing monomer, and tetrahydrofuran to the reactor, stir evenly, heat to 60-65℃, add a catalyst to the reactor for catalysis, keep warm for 4-8 hours, separate the product, wash and vacuum dry to obtain the linker.
[0018] As a further aspect of the present invention, in step one, the molar ratio of 1,4-bis(2-hydroxyethyl)piperazine and 2,3-dibromopropionic acid is 1:0.8-0.9.
[0019] As a further aspect of the present invention, in step one, the alkaline hydroxide aqueous solution is a sodium hydroxide aqueous solution or a potassium hydroxide aqueous solution, with a mass fraction of 15-25%.
[0020] As a further aspect of the present invention, in step two, the active phosphorus-containing monomer is any one of dimethyl chlorophosphate, diphenyl chlorophosphate, or 2-chloro-2-oxo-1,3,2-dioxophosphazenecyclopentane.
[0021] As a further aspect of the present invention, in step two, the catalyst is triethylamine or pyridine.
[0022] As a further embodiment of the present invention, the phase transfer catalyst is trifluoromethanesulfonic acid or p-toluenesulfonic acid.
[0023] In the above technical solution, 1,4-bis(2-hydroxyethyl)piperazine and 2,3-dibromopropionic acid are first used as polymerization monomers, and alkaline hydroxide is used for catalysis to allow the active hydroxyl groups and halogen substituents to undergo a continuous substitution reaction, thereby obtaining a nitrogen-containing intermediate with an alternating linkage structure. By controlling the ratio of the two, the nitrogen-containing intermediate can be made to exhibit hydroxyl-terminated structure. Then, the terminal hydroxyl groups of the intermediate are modified by using an active phosphorus-containing monomer to obtain the linker.
[0024] Because the block structure of the linker contains a large number of active carboxyl substituents, under the action of a phase transfer catalyst, it can condense with the substituted hydroxyl groups in the xylooligosaccharide structure and gradually produce cross-linking, so that the xylooligosaccharide forms a cross-linked gel structure. After freeze-drying, a flame retardant and smoke suppressant preparation with an aerogel structure can be obtained.
[0025] As a further embodiment of the present invention, the filler is any one of carbon black, fumed silica or titanium dioxide; the vulcanizing agent is sulfur; and the accelerator is benzoyl peroxide or dicumyl peroxide.
[0026] A flame-retardant rubber composition is prepared using the above-described production process.
[0027] (III) Beneficial Technical Effects
[0028] The flame-retardant and smoke-suppressing agent prepared by this invention has an aerogel structure. When combustion occurs, the special porous structure of the aerogel can effectively absorb the smoke generated by combustion, thereby inhibiting the emission of smoke and achieving the effect of smoke suppression. At the same time, the flame-retardant and smoke-suppressing agent contains a large amount of nitrogen elements and phosphorus-containing flame-retardant structures, which can provide gas and acid sources. The continuous structure of cross-linked xylooligosaccharides can serve as a carbon source. Therefore, it has the characteristics of a special three-in-one intumescent flame retardant and has excellent flame-retardant performance. Thus, it can achieve the effect of significantly improving the flame-retardant performance of natural rubber with a small amount of addition, avoiding the defects of using small molecule phosphorus-based flame retardants and inorganic flame retardants. Attached Figure Description
[0029] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of 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.
[0030] Figure 1 This is a scanning electron microscope image of a flame retardant and smoke-suppressing agent. Detailed Implementation
[0031] To facilitate understanding of the present invention, a more complete description will be provided below. Preferred embodiments of the invention are given below. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.
[0032] Preparation Example 1
[0033] Preparation of flame retardant and smoke-suppressing agents:
[0034] Step 1: Add 0.5g of 1,4-bis(2-hydroxyethyl)piperazine and toluene to a nitrogen-filled polymerization reactor and stir until homogeneous. Then add 5mL of 25% sodium hydroxide aqueous solution. After the addition is complete, control the temperature at 50℃ and mechanically stir for 2h. Continue to add 0.55g of 2,3-dibromopropionic acid to the polymerization reactor and raise the temperature to 75℃. Keep stirring at this temperature for 16h to obtain a nitrogen-containing intermediate.
[0035] Step 2: Add 0.8g of nitrogen-containing intermediate, 0.2g of 2-chloro-2-oxo-1,3,2-dioxophosphazenecyclopentane, and tetrahydrofuran to the reaction vessel, stir evenly, heat to 65℃, and add 0.5g of triethylamine to the reaction vessel for catalysis. After heat treatment for 6 hours, separate the product, wash and vacuum dry to obtain the linker;
[0036] Step 3: Add 5g of xylooligosaccharide to a 70% (v / v) ethanol aqueous solution and mechanically stir until homogeneous to form a mixture. Then add 1.2g of linker and 0.1g of p-toluenesulfonic acid to the mixture. After the addition is complete, purge with nitrogen for protection and raise the temperature to 80℃. After heat treatment for 9 hours, remove the nitrogen and stop heating. After the material cools down, pour it into a mold and let it stand to solidify. Then transfer the solidified material to a freeze dryer and freeze dry at -50℃ for 48 hours to obtain the flame retardant and smoke suppressant preparation.
[0037] Figure 1 The image shows a scanning electron microscope (SEM) image of the flame retardant and smoke suppressant. As can be seen from the image, it has a rich pore structure with a relatively uniform distribution, which can absorb the smoke generated during combustion and reduce the release of smoke.
[0038] Example 1
[0039] A flame-retardant rubber composition comprising the following raw materials measured in parts by weight:
[0040]
[0041] The production process of the rubber composition includes the following steps;
[0042] The first step is to weigh and prepare all the raw materials according to the weight proportions. Then, place the natural rubber on the open mill for plasticization, and then add the polybutadiene rubber and knead it to form a rubber compound.
[0043] Step 2: Add the rubber compound, flame retardant and smoke suppressant, carbon black, antioxidant, zinc oxide, benzoyl peroxide and microcrystalline wax into the internal mixer, control the temperature at 100℃, the rotor speed at 30rpm, and mix for 1min.
[0044] Third step: Continue to add sulfur to the internal mixer, control the temperature at 90℃, continue mixing for 1 minute, then transfer it to the vulcanizing agent, control the vulcanization temperature at 150℃, the rotation speed at 40 rpm, vulcanize for 30 minutes under a pressure of 10 MPa, then discharge the material and let it stand for 8 hours.
[0045] The preparation method of the flame retardant and smoke suppressant is shown in Preparation Example 1; the antioxidant used is antioxidant 4020, and the same applies to the following.
[0046] Example 2
[0047] A flame-retardant rubber composition comprising the following raw materials measured in parts by weight:
[0048]
[0049]
[0050] The production process of the rubber composition includes the following steps;
[0051] The first step is to weigh and prepare all the raw materials according to the weight proportions. Then, place the natural rubber on the open mill for plasticization, and then add the polybutadiene rubber and knead it to form a rubber compound.
[0052] The second step is to add the rubber compound, flame retardant and smoke suppressant, fumed silica, antioxidant, zinc oxide, dicumyl peroxide and microcrystalline wax into the internal mixer, control the temperature at 110℃, the rotor speed at 40rpm, and mix for 1min.
[0053] Third step: Continue to add sulfur to the internal mixer, control the temperature at 100℃, continue mixing for 1 minute, then transfer it to the vulcanizing agent, control the vulcanization temperature at 160℃, the rotation speed at 50 rpm, vulcanize for 40 minutes under a pressure of 10 MPa, then discharge the material and let it stand for 9 hours.
[0054] Example 3
[0055] A flame-retardant rubber composition comprising the following raw materials measured in parts by weight:
[0056]
[0057]
[0058] The production process of the rubber composition includes the following steps;
[0059] The first step is to weigh and prepare all the raw materials according to the weight proportions. Then, place the natural rubber on the open mill for plasticization, and then add the polybutadiene rubber and knead it to form a rubber compound.
[0060] The second step is to add the rubber compound, flame retardant and smoke suppressant, fumed silica, antioxidant, zinc oxide, dicumyl peroxide and microcrystalline wax into the internal mixer, control the temperature at 120℃, the rotor speed at 50rpm, and mix for 2 minutes.
[0061] Third step: Continue to add sulfur to the internal mixer, control the temperature at 100℃, continue mixing for 2 minutes, then transfer it to the vulcanizing agent, control the vulcanization temperature at 160℃, the rotation speed at 50 rpm, vulcanize for 40 minutes under a pressure of 15 MPa, then discharge the material and let it stand for 12 hours.
[0062] Comparative Example 1
[0063] A flame-retardant rubber composition comprising the following raw materials measured in parts by weight:
[0064]
[0065] The production process of the rubber composition includes the following steps;
[0066] The first step is to weigh and prepare all the raw materials according to the weight proportions. Then, place the natural rubber on the open mill for plasticization, and then add the polybutadiene rubber and knead it to form a rubber compound.
[0067] Step 2: Add the rubber compound, 2-chloro-2-oxo-1,3,2-dioxophosphorus cyclopentane, fumed silica, antioxidant, zinc oxide, diisopropylbenzene peroxide and microcrystalline wax into the internal mixer, control the temperature at 110℃, the rotor speed at 40 rpm, and mix for 1 min.
[0068] Third step: Continue to add sulfur to the internal mixer, control the temperature at 100℃, continue mixing for 1 minute, then transfer it to the vulcanizing agent, control the vulcanization temperature at 160℃, the rotation speed at 50 rpm, vulcanize for 40 minutes under a pressure of 10 MPa, then discharge the material and let it stand for 9 hours.
[0069] Comparative Example 2
[0070] A flame-retardant rubber composition comprising the following raw materials measured in parts by weight:
[0071]
[0072] The production process of the rubber composition includes the following steps;
[0073] The first step is to weigh and prepare all the raw materials according to the weight proportions. Then, place the natural rubber on the open mill for plasticization, and then add the polybutadiene rubber and knead it to form a rubber compound.
[0074] The second step is to add the rubber compound, fumed silica, antioxidant, zinc oxide, diisopropylbenzene peroxide and microcrystalline wax into the internal mixer, control the temperature at 110℃, the rotor speed at 40rpm, and mix for 1min.
[0075] Third step: Continue to add sulfur to the internal mixer, control the temperature at 100℃, continue mixing for 1 minute, then transfer it to the vulcanizing agent, control the vulcanization temperature at 160℃, the rotation speed at 50 rpm, vulcanize for 40 minutes under a pressure of 10 MPa, then discharge the material and let it stand for 9 hours.
[0076] Test case
[0077] According to standard GB / T 2406.2-2009, the limiting oxygen index of the rubber compositions in the examples and comparative examples was tested after being placed at room temperature for 2 months.
[0078] According to standard GB / T 8323-2008, the smoke density of the rubber compositions in the examples and comparative examples was tested;
[0079] The test results are recorded in the table below:
[0080] Limiting oxygen index / % Smoke density (with flame) Example 1 32.1 76 Example 2 32.4 73 Example 3 32.3 74 Comparative Example 1 27.8 109 Comparative Example 2 19.6 321
[0081] Analysis shows that using the flame-retardant and smoke-suppressing agent in Preparation Example 1 of this invention as an additive to modify natural rubber can effectively enhance the flame-retardant properties of natural rubber and suppress smoke release during combustion. Replacing it with a conventional small-molecule phosphorus-containing flame retardant resulted in poor flame-retardant modification due to long-term storage and subsequent dissipation.
[0082] Based on the preferred embodiments of the present invention, and through the above description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.
Claims
1. A production process for a rubber composition with flame-retardant properties, characterized in that, The rubber composition comprises the following raw materials measured in parts by weight: The production process includes the following steps; The first step is to weigh and prepare all the raw materials according to the weight proportions. Then, place the natural rubber on the open mill for plasticization, and then add the polybutadiene rubber and knead it to form a rubber compound. The second step is to add the rubber compound, flame retardant and smoke suppressant, filler, antioxidant, zinc oxide, accelerator and microcrystalline wax into the internal mixer, control the temperature at 100-120℃, the rotor speed at 30-50rpm, and mix for 1-2 minutes. Third step: Continue to add the vulcanizing agent to the internal mixer, control the temperature at 90-100℃, continue mixing for 1-2 minutes, then transfer it to the vulcanizing agent, control the vulcanization temperature at 150-160℃, the rotation speed at 40-50 rpm, vulcanize for 30-40 minutes under a pressure of 10-15 MPa, then discharge the material and let it stand for 8-12 hours.
2. The production process of a flame-retardant rubber composition according to claim 1, characterized in that, The specific preparation method of the flame-retardant and smoke-suppressing agent is as follows: Xylooligosaccharides are added to an ethanol aqueous solution with a volume fraction of 60-70% and mechanically stirred until homogeneous to form a mixture. Then, the linker and phase transfer catalyst are added to the mixture. After the addition is complete, nitrogen gas is introduced for protection, and the temperature is raised to 70-80℃. After heat treatment for 8-12 hours, the nitrogen gas is removed and heating is stopped. After the material cools down, it is poured into a mold and allowed to stand to form. Then, the formed material is transferred to a freeze dryer and freeze-dried at a temperature of -40-50℃ for 24-48 hours to obtain the flame retardant and smoke suppressant preparation.
3. The production process of a rubber composition with flame-retardant properties according to claim 2, characterized in that, The specific preparation method of the connector includes the following steps: Step 1: Add 1,4-bis(2-hydroxyethyl)piperazine and toluene to a nitrogen-filled polymerization reactor and stir until homogeneous. Then add an alkaline hydroxide aqueous solution. After the addition is complete, control the temperature at 50-60℃ and mechanically stir for 1-3 hours. Continue to add 2,3-dibromopropionic acid to the polymerization reactor and raise the temperature to 70-80℃. Keep the temperature and stir for 12-18 hours to obtain a nitrogen-containing intermediate. Step 2: Add the nitrogen-containing intermediate, the active phosphorus-containing monomer, and tetrahydrofuran to the reactor, stir evenly, heat to 60-65℃, add a catalyst to the reactor for catalysis, keep warm for 4-8 hours, separate the product, wash and vacuum dry to obtain the linker.
4. The production process of a rubber composition with flame-retardant properties according to claim 3, characterized in that, In step one, the molar ratio of 1,4-bis(2-hydroxyethyl)piperazine and 2,3-dibromopropionic acid is 1:0.8-0.
9.
5. The production process of a rubber composition with flame-retardant properties according to claim 3, characterized in that, In step one, the alkaline hydroxide aqueous solution is an aqueous solution of sodium hydroxide or potassium hydroxide, with a mass fraction of 15-25%.
6. The production process of a rubber composition with flame-retardant properties according to claim 3, characterized in that, In step two, the active phosphorus-containing monomer is any one of dimethyl chlorophosphate, diphenyl chlorophosphate, or 2-chloro-2-oxo-1,3,2-dioxophosphazenecyclopentane.
7. The production process of a rubber composition with flame-retardant properties according to claim 3, characterized in that, In step two, the catalyst is triethylamine or pyridine.
8. The production process of a rubber composition with flame-retardant properties according to claim 2, characterized in that, The phase transfer catalyst is trifluoromethanesulfonic acid or p-toluenesulfonic acid.
9. The production process of a rubber composition with flame-retardant properties according to claim 1, characterized in that, The filler is any one of carbon black, fumed silica, or titanium dioxide; the vulcanizing agent is sulfur; and the accelerator is benzoyl peroxide or dicumyl peroxide.
10. A rubber composition with flame-retardant properties as described in claim 1, characterized in that, It is produced using the manufacturing process described in any one of claims 1-9.