A butyl rubber blend resistant to multiple solvents and its preparation method

Abstract

This invention discloses a butyl rubber blend resistant to multiple solvents and its preparation method, belonging to the field of rubber preparation technology. First, brominated butyl rubber is added to a mixer for plasticizing. Then, magnesium oxide, stearic acid, antioxidant RD, antioxidant 4010NA, and a portion of microcrystalline wax are added to the mixer and mixed. Next, fast-extrusion carbon black and thermally pyrolyzed carbon black are added and mixed. Epoxidizing crosslinking agent, the remaining microcrystalline wax, and processing aids are then added and mixed. The mixture is transferred to a two-roll mill and sheeted to obtain masterbatch. Finally, the masterbatch is added to the two-roll mill, rolled, and then vulcanizing resin, zinc oxide, accelerator CZ, and sulfur are added sequentially. Sheeting yields the butyl rubber blend resistant to multiple solvents. The butyl rubber blend provided by this invention possesses excellent resistance to various solvents and superior physical and mechanical properties, meeting the technical requirements of foreign sample comparison tests.

Description

Technical Field

[0001] This invention relates to the field of rubber preparation technology, specifically to a butyl rubber blend resistant to multiple solvents and its preparation method. Background Technology

[0002] Butyl rubber, a synthetic rubber copolymerized from isobutylene and a small amount of isoprene, possesses a highly saturated molecular structure with a regular arrangement of side methyl groups. This endows it with low gas permeability, excellent shock absorption, good heat aging resistance, and weather resistance. Therefore, it is widely used in tire inner tubes, medical bottle stoppers, waterproof membranes, and various sealing products, becoming a key basic material for high-performance sealing solutions. In the sealing applications of daily-use spray containers (such as push-button spray valves for personal care products, detergents, and insecticides), butyl rubber is considered an ideal candidate material due to its excellent airtightness, ensuring that the contents are stored for extended periods without leakage or drying. However, currently, the high-performance butyl rubber materials used in the domestic high-end market, especially in daily-use spray seals involving complex chemical compositions, still largely rely on imports from Europe, creating a dependence on external supply for this key material.

[0003] Despite its numerous advantages, butyl rubber exhibits significant performance deficiencies when exposed to complex chemical environments, particularly various organic solvents, limiting its ability to meet the sealing requirements of high-end daily-use sprays. Daily-use spray products contain a complex and diverse range of organic solvents, often including alkanes (such as hexane and petroleum ether), aromatic hydrocarbons (such as toluene), halogenated hydrocarbons (such as dichloromethane and perchloroethylene), esters (such as ethyl acetate), ketones (such as acetone), alcohols (such as ethanol and isopropanol), and ethers (such as dimethyl ether). Traditional butyl rubber, especially ordinary butyl rubber, demonstrates strong resistance to many non-polar solvents, but its tolerance to strongly polar solvents and some halogenated hydrocarbons is severely insufficient. When exposed to solvents such as toluene, dichloromethane, and perchloroethylene, the rubber network undergoes severe swelling, leading to loss of dimensional stability of the seal, decreased sealing pressure, and even failure. Existing butyl rubber products struggle to maintain a low volume change rate after prolonged immersion in these solvents, directly resulting in their inability to pass stringent media resistance tests and thus limiting their application in demanding sealing scenarios. Therefore, it is essential to develop a new butyl rubber blend that is resistant to multiple solvents. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a butyl rubber blend resistant to various solvents and its preparation method. The main component is brominated butyl rubber, with the addition of a large-particle-size filled carbon black reinforcing agent. A special vulcanization system and an epoxidation crosslinking agent are used to form a special solvent-resistant rubber material formulation through internal mixing. This formulation not only has excellent resistance to various solvents but also meets the special requirements for good physical and mechanical properties of rubber materials.

[0005] The first aspect of this invention is to provide a butyl rubber blend resistant to multiple solvents, comprising the following components by mass parts: 100 parts brominated butyl rubber, 2-4 parts magnesium oxide, 1 part stearic acid, 1-2 parts antioxidant RD, 1-2 parts antioxidant 4010NA, 1.2-2.5 parts microcrystalline wax, 30-50 parts fast-extrusion carbon black, 50-70 parts thermal pyrolysis carbon black, 0.5-3 parts epoxidation crosslinking agent, 5-10 parts vulcanized resin, 2-5 parts zinc oxide, 0.5-1 part accelerator CZ, 0.5-1.5 parts sulfur, and 1-2 parts processing aids; The epoxidation crosslinking agent is prepared by the following steps: S1: Mix polypropylene glycol and tetrabutylammonium bromide, and add epichlorohydrin dropwise under ice-water bath cooling. After the addition is complete, proceed with the reaction. S2: Add sodium hydroxide solution dropwise to the reaction system of S1 and stir to react. After the reaction, cool and wash until neutral, separate the organic phase, and distill to obtain the epoxidized crosslinking agent.

[0006] It should be noted that this invention prepares an epoxidative crosslinking agent. Using a flexible polyether long chain (such as polypropylene glycol) as the backbone, a chlorohydrin intermediate is generated through a ring-opening addition reaction between the terminal hydroxyl groups and excess epichlorohydrin. This intermediate is then subjected to intramolecular ring closure under alkaline conditions, thereby synthesizing a polymer with highly active epoxy groups at both ends. During the mixing and vulcanization of rubber, these epoxy groups can undergo ring-opening reactions with the active bromine sites on the brominated butyl rubber molecular chain and the active groups on the surface of fillers such as carbon black, forming covalent bonds that bond the rubber matrix and filler interface, reducing defects. Furthermore, they can act as crosslinking points to strengthen the overall structure, constructing a denser and more stable system, limiting the penetration and swelling of solvent molecules, and improving the material's resistance to various strong solvents.

[0007] In this invention, the processing aid can be selected from plasticizers, dispersants, and internal release agents according to the actual situation.

[0008] In some embodiments, the mass ratio of polypropylene glycol to tetrabutylammonium bromide is 50:1.5-3.

[0009] In some embodiments, the polyoxypropylene glycol has a molecular weight of 1800-2200 and a hydroxyl value of 54-60 mg KOH / g.

[0010] In some embodiments, the mass of epichlorohydrin is 50-60% of the mass of polypropylene glycol.

[0011] In some embodiments, the sodium hydroxide solution concentration is 45-55%, and the mass amount of sodium hydroxide solution is 45-50% of the mass of polypropylene glycol.

[0012] In some embodiments, in S1, the mixing speed is 200-300 rpm, the dropping temperature is 5-15°C, the dropping time is 1-1.5 h, and the reaction is carried out at 58-62°C for 3.5-4.5 h.

[0013] In some embodiments, in S2, the dropping time is 30-40 min, the reaction temperature is 60-65 °C, and the reaction time is 1.5-2.5 h.

[0014] A second aspect of this invention provides a method for preparing a butyl rubber blend resistant to multiple solvents, comprising the following steps: (1) Add brominated butyl rubber to a mixer and masticate; (2) Add magnesium oxide, stearic acid, antioxidant RD, antioxidant 4010NA and some microcrystalline wax to the internal mixer and mix. Then add fast-extrusion carbon black and thermal pyrolysis carbon black and stir to mix. (3) Add epoxidizing crosslinking agent, remaining microcrystalline wax and processing aid to the mixing system in step (2), mix and transfer to a two-roll mill, and thin out to obtain masterbatch; (4) Add masterbatch to the open mill, wrap the rollers, and add vulcanizing resin, zinc oxide, accelerator CZ and sulfur in sequence. The resulting sheet is a butyl rubber blend resistant to a variety of solvents.

[0015] In some implementations, in step (1), the internal mixer temperature is 40-50℃, the rotation speed is 40-60rpm, and the plasticizing time is 2-3min; in step (2), the mixing temperature is <120℃, and the total mixing time is 6-8min.

[0016] In some implementations, in step (3), the mixing time is 3-5 min and the thin pass is 3-5 times; in step (4), the roller temperature is <60℃ and the sheet thickness is 5-6 mm.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention uses brominated butyl rubber as the main component, whose active bromine groups provide reaction sites for subsequent reinforcing crosslinking. Two different types of large-particle-size filled carbon black reinforcing agents are used to significantly improve elasticity and reduce compression heat generation. Simultaneously, a special resin-sulfur composite vulcanization system is used to construct a three-dimensional network with excellent heat resistance and stability. After mixing in an internal mixer, a special solvent-resistant rubber material formulation is formed. This material possesses excellent resistance to various solvents while simultaneously ensuring the corresponding physical and mechanical properties of rubber materials, meeting the technical requirements of foreign sample comparison tests. This lays a solid foundation for the domestic production of daily-use rubber sealing materials.

[0018] 2. This invention also creatively incorporates a multifunctional epoxidative crosslinking agent. The epoxy groups at both ends of the molecule can chemically react with the active sites of brominated butyl rubber and the surface of carbon black filler during vulcanization. This constructs additional, robust covalent bonds within the original physical vulcanization network and between the filler and rubber interface. This not only restricts the mobility of polymer chain segments in the solvent but also significantly hinders the penetration and diffusion pathways of solvent molecules (especially small-molecule strong solvents), achieving a fundamental strengthening of the network from physical blending to chemical bonding. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to specific embodiments.

[0020] Example 1 A butyl rubber blend resistant to multiple solvents, comprising the following components by mass parts: 100 parts brominated butyl rubber, 3 parts magnesium oxide, 1 part stearic acid, 1.5 parts antioxidant RD, 1.5 parts antioxidant 4010NA, 2 parts microcrystalline wax, 40 parts fast-extrusion carbon black, 60 parts thermal pyrolysis carbon black, 2 parts epoxidation crosslinking agent, 8 parts vulcanized resin, 3 parts zinc oxide, 0.8 parts accelerator CZ, 1 part sulfur, and 1.5 parts processing aids; The epoxidation crosslinking agent is prepared by the following steps: S1: Polypropylene glycol and tetrabutylammonium bromide in a mass ratio of 50:2 were mixed at 250 rpm, and epichlorohydrin was added dropwise over an ice-water bath at 10°C. The addition was completed within 1 hour, followed by a reaction at 60°C for 4 hours. The polypropylene glycol had a molecular weight of 2000 and a hydroxyl value of 56 mg KOH / g, and the mass of epichlorohydrin was 55% of the mass of polypropylene glycol. S2: Add a 50% sodium hydroxide solution dropwise to the reaction system of S1, stir the reaction at 65°C for 2 hours, and complete the addition within 35 minutes. After the reaction, cool and wash until neutral, separate the organic phase, and distill to obtain the epoxidized crosslinking agent; wherein, the mass of sodium hydroxide solution used is 48% of the mass of polypropylene glycol.

[0021] The above-mentioned butyl rubber blends resistant to multiple solvents were prepared by the following steps: (1) Add brominated butyl rubber (model 2828) to a mixer and plasticize at 45°C and 50 rpm for 3 min; (2) Add magnesium oxide, stearic acid, antioxidant RD, antioxidant 4010NA and half of the microcrystalline wax (model LSB20) to the internal mixer and mix. Then add fast extrusion carbon black (model N550) and thermal pyrolysis carbon black (model N990) and stir to mix. The mixing temperature in this stage is <120℃ and the total mixing time is 8min. (3) Add the epoxidizing crosslinking agent, the remaining half of the microcrystalline wax, and the processing aid (STRUKTOL) to the mixture from step (2). ® Mix A50) for 5 minutes, transfer to a two-roll mill, and pass through a thin mill 3-5 times to obtain the masterbatch; (4) Add masterbatch to the open mill, wrap the rollers, and add vulcanizing resin, zinc oxide, accelerator CZ and sulfur (200 mesh) in sequence. The resulting sheet is a butyl rubber blend resistant to various solvents. The open mill roller temperature is <60℃ and the sheet thickness is 6mm.

[0022] Example 2 A butyl rubber blend resistant to multiple solvents, comprising the following components by mass parts: 100 parts brominated butyl rubber, 4 parts magnesium oxide, 1 part stearic acid, 2 parts antioxidant RD, 2 parts antioxidant 4010NA, 2.5 parts microcrystalline wax, 50 parts fast-extrusion carbon black, 70 parts thermal pyrolysis carbon black, 3 parts epoxidation crosslinking agent, 10 parts vulcanizing resin, 5 parts zinc oxide, 1 part accelerator CZ, 1.5 parts sulfur, and 2 parts processing aids; The epoxidation crosslinking agent is prepared by the following steps: S1: Polypropylene glycol and tetrabutylammonium bromide were mixed at a mass ratio of 50:3 at 300 rpm, and epichlorohydrin was added dropwise over 1.5 h after cooling to 15 °C in an ice-water bath. The mixture was then reacted at 62 °C for 3.5 h. The polypropylene glycol had a molecular weight of 2200 and a hydroxyl value of 60 mg KOH / g, and the mass of epichlorohydrin was 60% of the mass of polypropylene glycol. S2: Add a 55% sodium hydroxide solution dropwise to the reaction system of S1, stir the reaction at 65°C for 2.5 h, and complete the addition within 40 min. After the reaction, cool and wash until neutral, separate the organic phase, and distill to obtain the epoxidized crosslinking agent; wherein, the mass of sodium hydroxide solution used is 50% of the mass of polyoxypropylene glycol.

[0023] The above-mentioned butyl rubber blends resistant to multiple solvents were prepared by the following steps: (1) Add brominated butyl rubber (model 2828) to a mixer and plasticize at 50°C and 60 rpm for 2 min; (2) Add magnesium oxide, stearic acid, antioxidant RD, antioxidant 4010NA and some microcrystalline wax (model LSB20) to the internal mixer and mix. Then add fast extrusion carbon black (model N550) and thermal decomposition carbon black (model N990) and stir to mix. The mixing temperature in this stage is <120℃ and the total mixing time is 8min. (3) Add the epoxidizing crosslinking agent, the remaining microcrystalline wax, and the processing aid (STRUKTOL) to the mixture from step (2). ® Mix WB16 for 5 minutes, transfer to a two-roll mill, and pass through a thin mill 5 times to obtain the masterbatch; (4) Add masterbatch to the open mill, wrap the rollers, and add vulcanizing resin, zinc oxide, accelerator CZ and sulfur (200 mesh) in sequence. The resulting sheet is a butyl rubber blend resistant to various solvents. The open mill roller temperature is <60℃ and the sheet thickness is 6mm.

[0024] Example 3 A butyl rubber blend resistant to multiple solvents, comprising the following components by mass parts: 100 parts brominated butyl rubber, 2 parts magnesium oxide, 1 part stearic acid, 1 part antioxidant RD, 1 part antioxidant 4010NA, 1.2 parts microcrystalline wax, 30 parts fast-extrusion carbon black, 50 parts thermal pyrolysis carbon black, 0.5 parts epoxidation crosslinking agent, 5 parts vulcanizing resin, 2 parts zinc oxide, 0.5 parts accelerator CZ, 0.5 parts sulfur, and 1 part processing aid; The epoxidation crosslinking agent is prepared by the following steps: S1: Polypropylene glycol and tetrabutylammonium bromide in a mass ratio of 50:1.5 were mixed at 200 rpm, and epichlorohydrin was added dropwise over an ice-water bath at 5°C. The addition was completed within 1 hour, followed by a reaction at 58°C for 4.5 hours. The polypropylene glycol had a molecular weight of 1800 and a hydroxyl value of 54 mg KOH / g, and the mass of epichlorohydrin was 50% of the mass of polypropylene glycol. S2: Add a 45% sodium hydroxide solution dropwise to the reaction system of S1, stir the reaction at 60°C for 1.5 h, and complete the addition within 30 min. After the reaction, cool and wash until neutral, separate the organic phase, and distill to obtain the epoxidized crosslinking agent; wherein, the mass of sodium hydroxide solution used is 45% of the mass of polypropylene glycol.

[0025] The above-mentioned butyl rubber blends resistant to multiple solvents were prepared by the following steps: (1) Add brominated butyl rubber (model 2828) to a mixer and plasticize at 40°C and 40 rpm for 3 min; (2) Add magnesium oxide, stearic acid, antioxidant RD, antioxidant 4010NA and some microcrystalline wax (model LSB20) to the internal mixer and mix. Then add fast extrusion carbon black (model N550) and thermal decomposition carbon black (model N990) and stir to mix. The mixing temperature in this stage is <120℃ and the total mixing time is 6min. (3) Add the epoxidizing crosslinking agent, the remaining microcrystalline wax, and the processing aid (STRUKTOL) to the mixture from step (2). ® Mix A50) for 3 minutes, transfer to a two-roll mill, and pass through a thin mill 3-5 times to obtain the masterbatch; (4) Add masterbatch to the open mill, wrap the rollers, and add vulcanizing resin, zinc oxide, accelerator CZ and sulfur (200 mesh) in sequence. The resulting sheet is a butyl rubber blend resistant to various solvents. The open mill roller temperature is <60℃ and the sheet thickness is 5mm.

[0026] Example 4 A butyl rubber blend resistant to multiple solvents, comprising the following components by mass parts: 100 parts brominated butyl rubber, 4 parts magnesium oxide, 1 part stearic acid, 2 parts antioxidant RD, 2 parts antioxidant 4010NA, 2.5 parts microcrystalline wax, 35 parts fast-extrusion carbon black, 55 parts thermal pyrolysis carbon black, 1 part epoxidation crosslinking agent, 6 parts vulcanizing resin, 3 parts zinc oxide, 0.6 parts accelerator CZ, 0.8 parts sulfur, and 2 parts processing aids; The epoxidation crosslinking agent is prepared by the following steps: S1: Polypropylene glycol and tetrabutylammonium bromide in a mass ratio of 50:2.5 were mixed at 250 rpm, and epichlorohydrin was added dropwise over an ice-water bath at 8°C. The addition was completed within 1.1 h, followed by a reaction at 60°C for 4 h. The polypropylene glycol had a molecular weight of 1900 and a hydroxyl value of 55 mg KOH / g, and the mass of epichlorohydrin was 52% of the mass of polypropylene glycol. S2: Add a 48% sodium hydroxide solution dropwise to the reaction system of S1, stir the reaction at 62°C for 2 hours, and complete the addition within 32 minutes. After the reaction, cool and wash until neutral, separate the organic phase, and distill to obtain the epoxidized crosslinking agent; wherein, the mass of sodium hydroxide solution used is 48% of the mass of polypropylene glycol.

[0027] The above-mentioned butyl rubber blends resistant to multiple solvents were prepared by the following steps: (1) Add brominated butyl rubber (model 2828) to a mixer and plasticize at 42°C and 45 rpm for 3 min; (2) Add magnesium oxide, stearic acid, antioxidant RD, antioxidant 4010NA and some microcrystalline wax (model LSB20) to the internal mixer and mix. Then add fast extrusion carbon black (model N550) and thermal decomposition carbon black (model N990) and stir to mix. The mixing temperature in this stage is <120℃ and the total mixing time is 8min. (3) Add the epoxidizing crosslinking agent, the remaining microcrystalline wax, and the processing aid (STRUKTOL) to the mixture from step (2). ® Mix WB16 for 5 minutes, transfer to a two-roll mill, and pass through a thin mill 4 times to obtain the masterbatch; (4) Add masterbatch to the open mill, wrap the rollers, and add vulcanizing resin, zinc oxide, accelerator CZ and sulfur (200 mesh) in sequence. The resulting sheet is a butyl rubber blend resistant to various solvents. The open mill roller temperature is <60℃ and the sheet thickness is 6mm.

[0028] Example 5 A butyl rubber blend resistant to multiple solvents, comprising the following components by mass parts: 100 parts brominated butyl rubber, 2 parts magnesium oxide, 1 part stearic acid, 2 parts antioxidant RD, 1 part antioxidant 4010NA, 2.5 parts microcrystalline wax, 45 parts fast-extrusion carbon black, 65 parts thermal pyrolysis carbon black, 2.5 parts epoxidation crosslinking agent, 9 parts vulcanized resin, 4 parts zinc oxide, 0.9 parts accelerator CZ, 1.2 parts sulfur, and 1.8 parts processing aids; The epoxidation crosslinking agent is prepared by the following steps: S1: Polypropylene glycol and tetrabutylammonium bromide in a mass ratio of 50:2.8 were mixed at 280 rpm, and epichlorohydrin was added dropwise over an ice-water bath at 12°C. The addition was completed within 1.4 h, followed by a reaction at 60°C for 4.5 h. The polypropylene glycol had a molecular weight of 2100 and a hydroxyl value of 58 mg KOH / g, and the mass of epichlorohydrin was 58% of the mass of polypropylene glycol. S2: Add a 53% sodium hydroxide solution dropwise to the reaction system of S1, stir the reaction at 63°C for 2.2 h, and complete the addition within 35 min. After the reaction, cool and wash until neutral, separate the organic phase, and distill to obtain the epoxidized crosslinking agent; wherein, the mass of sodium hydroxide solution used is 48% of the mass of polypropylene glycol.

[0029] The above-mentioned butyl rubber blends resistant to multiple solvents were prepared by the following steps: (1) Add brominated butyl rubber (model 2828) to a mixer and plasticize at 45°C and 55 rpm for 3 min; (2) Add magnesium oxide, stearic acid, antioxidant RD, antioxidant 4010NA and some microcrystalline wax (model LSB20) to the internal mixer and mix. Then add fast extrusion carbon black (model N550) and thermal decomposition carbon black (model N990) and stir to mix. The mixing temperature in this stage is <120℃ and the total mixing time is 8min. (3) Add the epoxidizing crosslinking agent, the remaining microcrystalline wax, and the processing aid (STRUKTOL) to the mixture from step (2). ® Mix WB16 for 5 minutes, transfer to a two-roll mill, and pass through a thin mill 5 times to obtain the masterbatch; (4) Add masterbatch to the open mill, wrap the rollers, and add vulcanizing resin, zinc oxide, accelerator CZ and sulfur (200 mesh) in sequence. The resulting sheet is a butyl rubber blend resistant to various solvents. The open mill roller temperature is <60℃ and the sheet thickness is 6mm.

[0030] Comparative Example 1 It is basically the same as Example 1, except that the brominated butyl rubber is replaced with the same amount of ordinary butyl rubber.

[0031] Comparative Example 2 It is basically the same as Example 1, except that only fast extrusion carbon black (model N550) is used, that is, the thermal pyrolysis carbon black (model N990) is replaced with the same amount of fast extrusion carbon black (model N550).

[0032] Comparative Example 3 It is basically the same as Example 1, except that only thermal pyrolysis carbon black (model N990) is used, that is, fast extrusion carbon black (model N550) is replaced with the same amount of thermal pyrolysis carbon black (model N990).

[0033] Comparative Example 4 It is basically the same as Example 1, except that no epoxidative crosslinking agent is added.

[0034] The rubbers prepared in Examples 1-5 and Comparative Examples 1-4 were subjected to performance tests, and the test results are shown in Tables 1-3.

[0035] Density was tested according to standard GB / T 1673-2001; Hardness was tested according to standard GB / T 531.1-2008; 100% tensile strength, tensile strength, elongation at break and permanent deformation at elongation were tested in accordance with standard GB / T 528-2009. The constant compressive permanent deformation was tested in accordance with standard GB / T 7759.1-2015; Liquid resistance performance is tested according to standard GB / T 1690, with a volume expansion rate ΔV over 56 days.

[0036] Table 1

[0037] Table 2

[0038] Table 3

[0039] As can be seen from the test results in Tables 1-3, the butyl rubber blends prepared in Examples 1-5 of this invention have good physical properties and chemical resistance. Brominated butyl rubber provides active bromine reaction sites. N550 and N990 are compounded to form a filled network. N550 provides strength support, N990 ensures elasticity and processability, and the epoxidation crosslinking agent binds the rubber molecular chains and carbon black particles more firmly. It also adds additional covalent crosslinking points to the original vulcanization network, forming an enhanced elastomer that is difficult for solvent molecules to penetrate, restricts chain segment movement, and can effectively resist swelling stress.

[0040] As can be seen from Comparative Examples 1-4, Comparative Example 1, which uses ordinary butyl rubber instead of brominated butyl rubber, loses its active bromine reaction sites, resulting in reduced reaction efficiency with the vulcanized resin. It cannot react with the epoxy groups of the epoxidative crosslinking agent, forming a system with low crosslinking density and a weak network. This leads to a significant decrease in physical properties and solvent resistance, and severe swelling in organic solvents. Comparative Example 2, using only N550 carbon black, significantly increases the hardness of the rubber compound and decreases its elasticity. When immersed in solvent, the rigid network lacks relaxation ability and is prone to defects under localized stress, exhibiting insufficient resistance to highly polar / penetrating solvents. Comparative Example 3, using only N990 carbon black, suffers from large particle size and poor reinforcing properties, failing to form effective physical support points. This results in severely insufficient rubber network strength, making it easily stretched apart in solvents, leading to poor physical properties and reduced resistance to solvent swelling. Comparative Example 4, without using an epoxidative crosslinking agent, relies solely on physical adsorption at the rubber-filler interface, making it more susceptible to damage and swelling under strong solvent attack, resulting in decreased physical properties and significantly reduced tolerance to strong solvents.

[0041] The above descriptions are merely some embodiments of the present invention. Those skilled in the art can make various modifications and improvements without departing from the inventive concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A butyl rubber blend resistant to multiple solvents, characterized in that, By mass parts, it includes the following components: 100 parts brominated butyl rubber, 2-4 parts magnesium oxide, 1 part stearic acid, 1-2 parts antioxidant RD, 1-2 parts antioxidant 4010NA, 1.2-2.5 parts microcrystalline wax, 30-50 parts fast-extrusion carbon black, 50-70 parts thermal pyrolysis carbon black, 0.5-3 parts epoxidation crosslinking agent, 5-10 parts vulcanized resin, 2-5 parts zinc oxide, 0.5-1 part accelerator CZ, 0.5-1.5 parts sulfur, and 1-2 parts processing aids; The epoxidation crosslinking agent is prepared by the following steps: S1: Mix polypropylene glycol and tetrabutylammonium bromide, and add epichlorohydrin dropwise under ice-water bath cooling. After the addition is complete, proceed with the reaction. S2: Add sodium hydroxide solution dropwise to the reaction system of S1 and stir to react. After the reaction, cool and wash until neutral, separate the organic phase, and distill to obtain the epoxidized crosslinking agent.

2. The butyl rubber blend resistant to multiple solvents according to claim 1, characterized in that, The mass ratio of polypropylene glycol to tetrabutylammonium bromide is 50:1.5-3.

3. The butyl rubber blend resistant to multiple solvents according to claim 2, characterized in that, The polyoxypropylene glycol has a molecular weight of 1800-2200 and a hydroxyl value of 54-60 mg KOH / g.

4. The butyl rubber blend resistant to multiple solvents according to claim 1, characterized in that, The mass of epichlorohydrin is 50-60% of the mass of polypropylene glycol.

5. The butyl rubber blend resistant to multiple solvents according to claim 1, characterized in that, The sodium hydroxide solution has a concentration of 45-55%, and the mass of the sodium hydroxide solution used is 45-50% of the mass of the polypropylene glycol.

6. The butyl rubber blend resistant to multiple solvents according to claim 1, characterized in that, In S1, the mixing speed is 200-300 rpm, the dropping temperature is 5-15℃, the dropping time is 1-1.5 h, and the reaction is carried out at 58-62℃ for 3.5-4.5 h.

7. The butyl rubber blend resistant to multiple solvents according to claim 1, characterized in that, In S2, the dropping time is 30-40 min, the reaction temperature is 60-65℃, and the reaction time is 1.5-2.5 h.

8. A method for preparing a butyl rubber blend resistant to multiple solvents as described in any one of claims 1-7, characterized in that, Includes the following steps: (1) Add brominated butyl rubber to a mixer and masticate; (2) Add magnesium oxide, stearic acid, antioxidant RD, antioxidant 4010NA and some microcrystalline wax to the internal mixer and mix. Then add fast-extrusion carbon black and thermal pyrolysis carbon black and stir to mix. (3) Add epoxidizing crosslinking agent, remaining microcrystalline wax and processing aid to the mixing system in step (2), mix and transfer to a two-roll mill, and thin out to obtain masterbatch; (4) Add the masterbatch to the open mill, wrap the rollers, and add the vulcanizing resin, zinc oxide, accelerator CZ and sulfur in sequence. The resulting sheet is the butyl rubber blend that is resistant to multiple solvents.

9. The method for preparing butyl rubber blends resistant to multiple solvents according to claim 8, characterized in that, In step (1), the internal mixer temperature is 40-50℃, the rotation speed is 40-60rpm, and the plasticizing time is 2-3min; in step (2), the mixing temperature is <120℃, and the total mixing time is 6-8min.

10. The method for preparing a butyl rubber blend resistant to multiple solvents according to claim 8, characterized in that, In step (3), the mixing time is 3-5 minutes, and the thin pass is 3-5 times; in step (4), the roller temperature is <60℃, and the thickness of the sheet is 5-6 mm.

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