Anti-migration halogenated butyl rubber composition as well as preparation method and application thereof

Abstract

The invention discloses an anti-migration halogenated butyl rubber composition as well as a preparation method and application thereof. The anti-migration halogenated butyl rubber composition comprises the following components in parts by weight: 100 parts of main halogenated butyl rubber; 5-30 parts of liquid halogenated butyl rubber; 30 to 80 parts of a reinforcing filler; 3-15 parts of a vulcanizing aid system; 1-10 parts of a functional auxiliary agent; wherein the weight-average molecular weight of the liquid halogenated butyl rubber is 20000-30000, the halogen content is 0.5 wt%-2.5 wt%, and a molecular chain contains an active halogen functional group. The liquid halogenated butyl rubber (L-XIIR) with a specific molecular weight range and halogen content is adopted as a reactive plasticizer, the liquid halogenated butyl rubber and the main body halogenated butyl rubber are subjected to a co-vulcanization reaction in the vulcanization process, so that a plasticized chain segment is chemically fixed in a three-dimensional cross-linked network, the process is simple, industrial production is easy, and the method is suitable for industrial production. And the low-temperature flexible lifting and migration problems are fundamentally solved.

Description

Technical Field

[0001] This invention relates to the field of rubber and polymer materials technology, and in particular to an anti-migration halogenated butyl rubber composition, its preparation method and application. Background Technology

[0002] Halogenated butyl rubber (XIIR, including brominated butyl BIIR and chlorinated butyl CIIR) is widely used in tire airtight layers and various sealing products due to its high main chain saturation, resulting in extremely low gas permeability and good weather resistance. However, when used in extreme low-temperature environments such as aircraft tires and cold-weather vehicle tires, the low-temperature brittleness temperature (Tb) of traditional solid halogenated butyl rubber is relatively high, typically -45°C to -40°C, making it difficult to meet the requirement of maintaining flexibility below -55°C.

[0003] To improve low-temperature flexibility, existing technologies typically employ the addition of small-molecule plasticizers such as naphthenic oil and paraffin oil. However, these traditional plasticizers have the following significant drawbacks: (1) They are highly mobile, and during vulcanization and long-term use, small-molecule plasticizers are prone to seeping out of the rubber matrix, leading to a gradual decline in low-temperature performance; (2) They impair airtightness, leaving micropores after plasticizer migration, which damages the dense structure of the material and reduces gas barrier performance; (3) They contaminate adjacent layers, and the exudate may contaminate adjacent rubber layers or fabrics, reducing the reliability of interlayer adhesion; (4) They cause mechanical property degradation, as plasticizers are not chemically bonded to the rubber network, and long-term use can easily lead to a decrease in mechanical properties such as tensile strength and tear strength; (5) They have poor durability and cannot maintain stable performance under harsh conditions such as temperature cycling and dynamic stress.

[0004] Some literature suggests using liquid rubber as a plasticizing component, but its molecular weight is usually too low (<10,000) or lacks sufficient active halogen sites to participate in the vulcanization reaction, still exhibiting a significant migration tendency, thus failing to fundamentally solve the aforementioned problems. Other studies have attempted to use high molecular weight liquid rubber, but due to its excessively high viscosity, it is difficult to disperse uniformly during the mixing process, affecting the performance consistency of the final product.

[0005] Therefore, there is an urgent need in the field for a rubber composition that can significantly reduce the brittle temperature of halogenated butyl rubber, ensure long-term stability of low-temperature performance without migration, and maintain excellent airtightness and mechanical properties, while also requiring the composition to have good processing performance and process adaptability. Summary of the Invention

[0006] The purpose of this invention is to provide an anti-migration halogenated butyl rubber composition, its preparation method, and its application, to solve at least one of the above-mentioned technical problems. It uses liquid halogenated butyl rubber (L-XIIR) with a specific molecular weight range and halogen content as a reactive plasticizer, which undergoes a co-vulcanization reaction with the main halogenated butyl rubber during vulcanization, thereby chemically fixing the plasticizing segments in a three-dimensional cross-linked network. The process is simple and easy to industrialize, fundamentally improving low-temperature flexibility and solving the migration problem.

[0007] The embodiments of the present invention are implemented as follows:

[0008] An anti-migration halogenated butyl rubber composition comprising the following components in parts by weight:

[0009] Main component: 100 parts of halogenated butyl rubber.

[0010] 5-30 parts of liquid halogenated butyl rubber.

[0011] 30-80 parts of reinforcing filler.

[0012] Vulcanizing aid system: 3-15 parts.

[0013] Functional additives, 1-10 parts.

[0014] The liquid halogenated butyl rubber has a weight-average molecular weight of 20,000 to 30,000 and a halogen content of 0.5 wt% to 2.5 wt%. Its molecular chain contains active halogen functional groups, which can undergo co-vulcanization reaction with the main halogenated butyl rubber under vulcanization conditions.

[0015] The technical advantages are as follows: A specific molecular weight range of liquid halogenated butyl rubber is selected as the reactive plasticizer, which combines good flowability and dispersibility with sufficient active halogen content. The optimized proportions of each component ensure excellent airtightness and mechanical properties while maintaining low-temperature flexibility.

[0016] In a preferred embodiment of the present invention, the liquid halogenated butyl rubber in the above-mentioned anti-migration halogenated butyl rubber composition includes at least one of liquid brominated butyl rubber and liquid chlorinated butyl rubber.

[0017] In a preferred embodiment of the present invention, the main halogenated butyl rubber in the above-mentioned anti-migration halogenated butyl rubber composition includes at least one of brominated butyl rubber and chlorinated butyl rubber.

[0018] The iodine value of the main halogenated butyl rubber is in the range of 1 to 2.

[0019] In a preferred embodiment of the present invention, the reinforcing filler in the above-mentioned anti-migration halogenated butyl rubber composition includes at least one of carbon black, silica, calcium carbonate and kaolin.

[0020] In a preferred embodiment of the present invention, the vulcanization aid system in the above-mentioned anti-migration halogenated butyl rubber composition comprises the following components in parts by weight:

[0021] Zinc oxide 1 to 5 parts.

[0022] Stearic acid 1-3 parts.

[0023] Sulfur 0.5 to 2 parts.

[0024] Accelerator DM 0.5-2 parts.

[0025] In a preferred embodiment of the present invention, the functional additives in the above-mentioned anti-migration halogenated butyl rubber composition include at least one of antioxidants, homogenizers, tackifying resins, and processing aids.

[0026] A method for preparing an anti-migration halogenated butyl rubber composition, comprising:

[0027] S100 involves plasticizing the main halogenated butyl rubber in an internal mixer to obtain plasticized rubber.

[0028] S200, liquid halogenated butyl rubber is added to the plasticized rubber and mixed evenly to obtain halogenated butyl blend.

[0029] S300, adding reinforcing fillers and functional additives to the halogenated butyl blend, and mixing evenly to obtain sulfur-free compound.

[0030] S400: After the temperature of the sulfur-free compound drops below 100°C, a vulcanization aid system is added and the compound is mixed. The mixture is then extruded through a tablet press to obtain a vulcanized rubber compound.

[0031] S500, the vulcanized rubber compound is subjected to compression molding vulcanization, so that the liquid halogenated butyl rubber and the main halogenated butyl rubber undergo a co-vulcanization reaction to obtain an anti-migration halogenated butyl rubber composition.

[0032] The anti-migration halogenated butyl rubber composition is the anti-migration halogenated butyl rubber composition as described above.

[0033] Its technical effect lies in the fact that liquid halogenated butyl rubber is chemically fixed in the cross-linked network through co-vulcanization reaction, thereby achieving permanent plasticization.

[0034] In a preferred embodiment of the present invention, in the preparation method of the above-mentioned anti-migration halogenated butyl rubber composition, in S100, the internal mixer is first preheated to 70°C, and then the main halogenated butyl rubber is added, with a plasticizing time of 2 minutes.

[0035] In S200, after adding the liquid halogenated butyl rubber, it is mixed at 80°C for 4 minutes.

[0036] In S300, the mixing temperature reaches 120°C.

[0037] In S500, the vulcanized rubber compound is molded and vulcanized at 160°C and 15MPa for 20 minutes.

[0038] In a preferred embodiment of the present invention, in the preparation method of the above-mentioned anti-migration halogenated butyl rubber composition, in step S400, the temperature of the sulfur-free compound is lowered to below 90°C.

[0039] Application of an anti-migration halogenated butyl rubber composition in the preparation of tire airtight layers, seals, protective films or shock-absorbing products.

[0040] The anti-migration halogenated butyl rubber composition is the anti-migration halogenated butyl rubber composition as described above.

[0041] The beneficial effects of the embodiments of the present invention are:

[0042] The anti-migration halogenated butyl rubber composition prepared by this invention has significantly improved low-temperature performance, with its brittle temperature reduced to below -55°C, and as low as -62°C, greatly enhancing the flexibility and applicability of the material in extreme low-temperature environments.

[0043] The anti-migration halogenated butyl rubber composition prepared by this invention has excellent anti-migration properties. Through co-vulcanization fixation technology, the liquid halogenated butyl rubber will not migrate from the rubber network, and its performance is stable over long-term use.

[0044] The anti-migration halogenated butyl rubber composition prepared by this invention has high air tightness retention, avoids the decrease in air tightness caused by plasticizer migration, and reduces the air permeability by more than 20% compared with the traditional system.

[0045] The anti-migration halogenated butyl rubber composition prepared by this invention has balanced mechanical properties, and while significantly improving low-temperature flexibility, it maintains good tensile strength, tear strength and fatigue resistance.

[0046] The anti-migration halogenated butyl rubber composition prepared by this invention has excellent processing performance. The liquid halogenated butyl rubber has good flowability and dispersibility, and is easy to mix and process.

[0047] The anti-migration halogenated butyl rubber composition prepared by this invention has outstanding durability. After accelerated tests such as high and low temperature cycling and thermo-oxidative aging, its performance retention rate is significantly higher than that of traditional systems. Attached Figure Description

[0048] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 This is a schematic diagram of the preparation method of the anti-migration halogenated butyl rubber composition of the present invention. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0051] The first embodiment of the present invention provides an anti-migration halogenated butyl rubber composition comprising the following components in parts by weight: 100 parts of main halogenated butyl rubber; 5-30 parts of liquid halogenated butyl rubber; 30-80 parts of reinforcing filler; 3-15 parts of vulcanization auxiliaries; and 1-10 parts of functional auxiliaries. The liquid halogenated butyl rubber has a weight-average molecular weight of 20,000-30,000, a halogen content of 0.5 wt%-2.5 wt%, and contains active halogen functional groups on its molecular chain, enabling it to undergo co-vulcanization with the main halogenated butyl rubber under vulcanization conditions.

[0052] The technical advantages are as follows: A specific molecular weight range of liquid halogenated butyl rubber is selected as the reactive plasticizer, which combines good flowability and dispersibility with sufficient active halogen content. The optimized proportions of each component ensure excellent airtightness and mechanical properties while maintaining low-temperature flexibility.

[0053] In a preferred embodiment of the present invention, the liquid halogenated butyl rubber in the above-mentioned anti-migration halogenated butyl rubber composition includes at least one of liquid brominated butyl rubber and liquid chlorinated butyl rubber.

[0054] Preferably, the liquid halogenated butyl rubber has a weight-average molecular weight of 22,000 to 28,000 and a halogen content of 1 wt% to 2 wt%.

[0055] In a preferred embodiment of the present invention, in the above-mentioned anti-migration halogenated butyl rubber composition, the main halogenated butyl rubber includes at least one of brominated butyl rubber (BIIR) and chlorinated butyl rubber (CIIR); the iodine value of the main halogenated butyl rubber is in the range of 1 to 2.

[0056] In a preferred embodiment of the present invention, the reinforcing filler in the above-mentioned anti-migration halogenated butyl rubber composition includes at least one of carbon black, silica, calcium carbonate and kaolin.

[0057] Preferably, the reinforcing filler is carbon black N550 or N660.

[0058] In a preferred embodiment of the present invention, the above-mentioned anti-migration halogenated butyl rubber composition comprises the following components in parts by weight: 1-5 parts zinc oxide; 1-3 parts stearic acid; 0.5-2 parts sulfur; and 0.5-2 parts accelerator DM.

[0059] In a preferred embodiment of the present invention, the functional additives in the above-mentioned anti-migration halogenated butyl rubber composition include at least one of antioxidants, homogenizers, tackifying resins, and processing aids.

[0060] Please refer to Figure 1 The second embodiment of the present invention provides a method for preparing an anti-migration halogenated butyl rubber composition, comprising: S100, plasticizing the main halogenated butyl rubber in a mixer to obtain a plasticized rubber compound; S200, adding liquid halogenated butyl rubber to the plasticized rubber compound and mixing evenly to obtain a halogenated butyl blend; S300, adding reinforcing fillers and functional additives to the halogenated butyl blend and mixing evenly to obtain a sulfur-free compound; S400, after the temperature of the sulfur-free compound has dropped below 100°C, adding a vulcanization aid system and mixing, and extruding the compound through a sheeting machine to prepare a vulcanized rubber compound; S500, subjecting the vulcanized rubber compound to compression molding vulcanization, causing the liquid halogenated butyl rubber and the main halogenated butyl rubber to undergo a co-vulcanization reaction to obtain an anti-migration halogenated butyl rubber composition; wherein the anti-migration halogenated butyl rubber composition is the anti-migration halogenated butyl rubber composition as described above.

[0061] Its technical effect lies in the fact that liquid halogenated butyl rubber is chemically fixed in the cross-linked network through co-vulcanization reaction, thereby achieving permanent plasticization.

[0062] In a preferred embodiment of the present invention, in the preparation method of the above-mentioned anti-migration halogenated butyl rubber composition, in S100, the internal mixer is preheated to 70°C, and then the main halogenated butyl rubber is added, with a plasticizing time of 2 minutes; in S200, after adding the liquid halogenated butyl rubber, it is mixed at 80°C for 4 minutes; in S300, the mixing temperature reaches 120°C; in S500, the vulcanized rubber compound is molded and vulcanized at 160°C and 15MPa for 20 minutes.

[0063] In a preferred embodiment of the present invention, in the preparation method of the above-mentioned anti-migration halogenated butyl rubber composition, in step S400, the temperature of the sulfur-free compound is lowered to below 90°C.

[0064] A third embodiment of the present invention provides the application of an anti-migration halogenated butyl rubber composition in the preparation of tire airtight layers, seals, protective films, or shock-absorbing products.

[0065] The anti-migration halogenated butyl rubber composition is the anti-migration halogenated butyl rubber composition as described above.

[0066] Specifically, the halogenated butyl rubber composition is prepared using the following process according to the formulation shown in Table 1:

[0067] S100, preheat the internal mixer to 70°C, and plasticize the main halogenated butyl rubber in the internal mixer for 2 minutes to obtain plasticized rubber.

[0068] S200, liquid halogenated butyl rubber is added to the plasticized rubber and mixed at 80°C for 4 minutes to obtain halogenated butyl blend.

[0069] S300, adding reinforcing fillers and functional additives to the halogenated butyl blend, mixing evenly, and the mixing temperature reaches 120℃ to obtain sulfur-free compound.

[0070] S400: After the temperature of the sulfur-free compound drops below 90°C, a vulcanization aid system is added and the compound is mixed. The mixture is then extruded through a tablet press to obtain a vulcanized rubber compound.

[0071] S500, the vulcanized rubber compound is subjected to compression molding vulcanization at 160°C and 15MPa for 20 minutes, so that the liquid halogenated butyl rubber and the main halogenated butyl rubber undergo a co-vulcanization reaction to obtain an anti-migration halogenated butyl rubber composition.

[0072] Table 1: Formulations of Examples and Comparative Examples (by weight parts)

[0073]

[0074] The performance of the vulcanized rubber samples prepared in the above embodiments and comparative examples was tested, and the results are shown in Table 2.

[0075] The test content and methods include:

[0076] (1) Air permeability, tested according to GB / T 1038-2000;

[0077] (2) Tensile properties, tested according to GB / T 528-2009;

[0078] (3) Tear strength, tested according to GB / T 529-2008;

[0079] (4) Brittleness temperature, tested according to GB / T 1682-2014;

[0080] (5) Migration mass loss rate, tested according to ASTM D925-14, 70℃×20d;

[0081] (6) Pollution level: The sample was bonded to a white nylon film and kept at 70℃ and 0.5MPa for 168h before observation;

[0082] (7) Aging resistance: After aging in hot air at 100℃ for 72 hours according to GB / T 3512-2014, tensile properties are tested according to GB / T 528-2009, and the tensile volume retention rate after aging is calculated.

[0083] Table 2: Comparison of Performance Test Results

[0084]

[0085] The analysis results are shown in Table 2:

[0086] (1) The brittle temperature of all embodiments is below -50°C, with Embodiments 3 and 6 reaching -60°C and -58°C respectively, which are significantly improved compared to the comparative examples;

[0087] (2) The air permeability of the embodiment is significantly lower than that of the comparative embodiment, and the air tightness is better;

[0088] (3) In terms of mechanical properties, the tensile strength and tear strength of the embodiment are superior to those of the comparative example;

[0089] (4) Regarding anti-migration performance, the migration quality loss rate of the embodiment is only 0.3-0.6%, which is much lower than the 5.2-5.8% of the comparative example;

[0090] (5) In the pollution level test, the example was basically free of pollution, while the comparative example showed obvious pollution;

[0091] (6) In terms of aging performance, the tensile volume retention rate of the embodiment is significantly higher than that of the comparative example.

[0092] It is particularly noteworthy that as the amount of liquid halogenated butyl rubber increases, the brittle temperature decreases further, but the tensile strength also decreases. In practical applications, the amount of liquid halogenated butyl rubber added can be adjusted according to specific performance requirements; generally, 10-20 parts can achieve the best overall performance.

[0093] The embodiments of the present invention aim to protect a migration-resistant halogenated butyl rubber composition, its preparation method and application, and have the following effects:

[0094] By employing liquid halogenated butyl rubber of a specific molecular weight as a reactive plasticizer and optimizing the formulation design, a halogenated butyl rubber composition with stable high and low temperature performance and anti-migration properties has been successfully developed. This composition significantly improves low-temperature flexibility while maintaining excellent airtightness and mechanical properties, solving the performance degradation problem caused by the migration of traditional plasticizers, and has significant industrial application value.

[0095] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of the invention and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of the invention should be included within the protection scope of the invention. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A migration-resistant halogenated butyl rubber composition, characterized in that, The components include the following parts by weight: Main component: 100 parts of halogenated butyl rubber; 5-30 parts of liquid halogenated butyl rubber; 30-80 parts of reinforcing filler; 3-15 parts of vulcanizing aid system; Functional additives, 1-10 parts; The liquid halogenated butyl rubber has a weight-average molecular weight of 20,000 to 30,000, a halogen content of 0.5 wt% to 2.5 wt%, and contains active halogen functional groups on its molecular chain.

2. The anti-migration halogenated butyl rubber composition according to claim 1, characterized in that, The liquid halogenated butyl rubber includes at least one of liquid brominated butyl rubber and liquid chlorinated butyl rubber.

3. The anti-migration halogenated butyl rubber composition according to claim 1, characterized in that, The main halogenated butyl rubber includes at least one of brominated butyl rubber and chlorinated butyl rubber; The iodine value of the main halogenated butyl rubber is in the range of 1 to 2.

4. The anti-migration halogenated butyl rubber composition according to claim 1, characterized in that, The reinforcing filler includes at least one of carbon black, silica, calcium carbonate, and clay.

5. The anti-migration halogenated butyl rubber composition according to claim 1, characterized in that, The vulcanization aid system comprises the following components in parts by weight: 1-5 parts zinc oxide; 1-3 parts stearic acid; Sulfur 0.5 to 2 parts; Accelerator DM 0.5-2 parts.

6. The anti-migration halogenated butyl rubber composition according to claim 1, characterized in that, The functional additives include at least one of antioxidants, homogenizers, tackifying resins, and processing aids.

7. A method for preparing an anti-migration halogenated butyl rubber composition, characterized in that, include: S100, the main halogenated butyl rubber is plasticized in an internal mixer to obtain plasticized rubber; S200, liquid halogenated butyl rubber is added to the plasticized rubber and mixed evenly to obtain halogenated butyl blend; S300, adding reinforcing fillers and functional additives to the halogenated butyl blend, and mixing evenly to obtain sulfur-free compound; S400: After the temperature of the sulfur-free compound drops below 100°C, add the vulcanization aid system and mix. Then, extrude the compound through a tablet press to obtain the vulcanized rubber material. S500, the vulcanized rubber compound is subjected to compression molding vulcanization, so that the liquid halogenated butyl rubber and the main halogenated butyl rubber undergo a co-vulcanization reaction to obtain an anti-migration halogenated butyl rubber composition. The anti-migration halogenated butyl rubber composition is the anti-migration halogenated butyl rubber composition as described in any one of claims 1-6.

8. The method for preparing the anti-migration halogenated butyl rubber composition according to claim 7, characterized in that, In S100, the internal mixer is first preheated to 70°C, and then the main halogenated butyl rubber is added. The plasticizing time is 2 minutes. In S200, after adding the liquid halogenated butyl rubber, it is mixed at 80°C for 4 minutes. In S300, the mixing temperature reaches 120°C; In S500, the vulcanized rubber compound is molded and vulcanized at 160°C and 15MPa for 20 minutes.

9. The method for preparing the anti-migration halogenated butyl rubber composition according to claim 7, characterized in that, In S400, the temperature of the sulfur-free compound is lowered to below 90°C.

10. The application of an anti-migration halogenated butyl rubber composition in the preparation of tire airtight layers, seals, protective films or shock-absorbing products; The anti-migration halogenated butyl rubber composition is the anti-migration halogenated butyl rubber composition as described in any one of claims 1-6.

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