A rubber composite material and a preparation method thereof

Abstract

The present invention discloses a rubber composite material and a preparation method thereof, belonging to the technical field of rubber materials and their preparation. The rubber composite material provided by the present invention comprises an olefin rubber, a plasticizer, a reinforcing filler, an activator, a vulcanizing agent, an antioxidant and an accelerator, wherein the olefin rubber is composed of natural rubber, styrene-butadiene rubber, cis-butadiene rubber and iron-catalyzed butene-pentene rubber. The composite material provided by the present invention significantly improves the heat resistance of the rubber composite material on the basis of having good resilience, mechanical properties and vulcanization rate by introducing butene-pentene rubber with high vinyl and propylene side group contents polymerized by an iron-based catalyst. Moreover, by adding a radiation-resistant additive and a silane coupling agent on the basis of the above composition raw materials, a rubber composite material with radiation-resistant properties can be further obtained. The present invention further improves the heat resistance and radiation resistance of the rubber material on the basis of ensuring that the rubber material has good resilience, mechanical properties and vulcanization rate.

Description

Technical Field

[0001] The present invention relates to a high heat-resistant rubber composite material and a preparation method thereof, belonging to the technical field of rubber materials and their preparation. Background Art

[0002] High heat-resistant rubbers are widely used due to their excellent heat resistance. However, with the continuous development of society, higher requirements are put forward for the high heat resistance and radiation resistance of rubbers. Therefore, high heat-resistant rubbers and radiation-resistant rubbers have become the focus of many researchers. The methods to improve the high heat resistance of rubbers are as follows: firstly, select a raw rubber system with high heat resistance; secondly, select an appropriate vulcanization system and reinforcing system to improve the high heat resistance of vulcanized rubbers; finally, select a stabilizer with excellent performance to improve the resistance of rubbers to the thermal-oxidative environment. The molecular structure of rubbers plays a decisive role in the high heat resistance and radiation resistance of rubbers. Therefore, the selection of raw rubber is crucial for improving the high heat resistance and radiation resistance of rubber materials. The common high heat-resistant rubbers on the market at present include silicone rubber, fluororubber and ethylene propylene diene monomer rubber. These rubber types have good heat resistance but have disadvantages such as too long vulcanization time and poor resilience. The heat resistance and radiation resistance of natural rubber, styrene-butadiene rubber and cis-1,4-polybutadiene rubber with acceptable vulcanization time are relatively low. Therefore, it is of great significance to develop a rubber with high heat resistance, radiation resistance, high vulcanization rate and high resilience. Summary of the Invention

[0003] Based on ensuring that the rubber material has good resilience, mechanical properties and vulcanization rate, the present invention further improves the heat resistance and radiation resistance of the rubber material, and provides a high heat-resistant rubber composite material and a radiation-resistant rubber composite material.

[0004] The technical solution of the present invention:

[0005] One of the purposes of the present invention is to provide a high heat-resistant rubber composite material, which is composed of the following raw materials in parts by weight:

[0006] 100 parts of olefin rubber;

[0007] 10 - 50 parts of plasticizer;

[0008] 20 - 80 parts of reinforcing filler;

[0009] 1 - 10 parts of activator;

[0010] 1 - 4 parts of vulcanizing agent;

[0011] 1 - 5 parts of accelerator;

[0012] 1 - 5 parts of antioxidant;

[0013] Among them, the olefin rubber is composed of 0-60 parts by weight of natural rubber, 0-60 parts by weight of styrene-butadiene rubber, 0-60 parts by weight of cis-butadiene rubber and 40-80 parts by weight of butadiene-pentene rubber. The parts of natural rubber, styrene-butadiene rubber and cis-butadiene rubber are not all 0 at the same time. The molecular weight of butadiene-pentene rubber is 500,000-700,000, Tg is -30°C to -10°C, the side group content is 40%-65%, and the side groups are vinyl and propenyl.

[0014] Further defined, the butadiene-pentene rubber is prepared by coordination polymerization of monomer isoprene and monomer butadiene using an iron-based catalyst. During the preparation process, the molar ratio of monomer butadiene to isoprene is 1:1.

[0015] Further defined, the butadiene-pentene rubber is an iron-based catalytic butadiene-pentene rubber without gel.

[0016] Further defined, the butadiene-pentene rubber is composed of 3,4-isoprene, 1,4-isoprene, 1,2-butadiene and 1,4-butadiene structural units.

[0017] More specifically defined, the molar content of 1,2-butadiene is 40%-60%, and the total molar content of cis-1,4-butadiene and trans-1,4-butadiene is 40%-60%; the molar content of 3,4-isoprene is 50%-70%, and the total molar content of cis-1,4-isoprene and trans-1,4-isoprene is 30%-50%.

[0018] Further defined, the plasticizer is one or a mixture of paraffin oil, aromatic oil, petrolatum, petroleum asphalt and transformer oil.

[0019] Further defined, the reinforcing filler is one or a mixture of carbon black, white carbon black, fumed silica, calcium carbonate, mica powder, hard kaolin, barium sulfate, magnesium sulfate, asbestos powder.

[0020] Further defined, the activator is zinc oxide and stearic acid.

[0021] More specifically defined, the addition amount of zinc oxide is 0.5-5 parts, and the addition amount of stearic acid is 0.5-5 parts.

[0022] Further defined, the vulcanizing agent is one or a mixture of phenolic resin, dicumyl peroxide, sulfur.

[0023] Further defined, the accelerator is one or a mixture of sulfenamide vulcanization accelerators, thiazole vulcanization accelerators, thiuram vulcanization accelerators and guanidine vulcanization accelerators.

[0024] Further defined, the sulfenamide accelerator is one or a mixture of more than one of N-cyclohexyl-2-benzothiazole sulfenamide, N-oxydi(1,2-ethylene)-2-benzothiazole sulfenamide, N,N-dicyclohexyl-2-benzothiazole sulfenamide, tetramethylthiuram disulfide, and tetramethylthiuram monosulfide.

[0025] Further defined, the antioxidant is one or a mixture of more than one of antioxidant RD, antioxidant D, antioxidant 4020, antioxidant A, antioxidant MB, and thio-bisnaphthol.

[0026] The second object of the present invention is to provide a method for preparing a highly heat-resistant rubber composite material, and the method includes the following steps:

[0027] Step 1, rubber plasticizing: In an internal mixer, with a filling coefficient of 0.6 to 0.8, add natural rubber, styrene-butadiene rubber, cis-butadiene rubber, and butyl pentene rubber for plasticizing. The plasticizing temperature is 120 to 135 °C, and the plasticizing time is 180 to 240 s. After plasticizing, obtain plasticized rubber.

[0028] Step 2, masterbatch mixing: In an internal mixer, with a filling coefficient of 0.6 to 0.8, put the plasticized rubber parked for more than 4 h, reinforcing filler, activator, and antioxidant into the internal mixer for mixing. The mixing temperature is 135 to 150 °C, and the mixing time is 240 to 300 s. After mixing, obtain a mixed masterbatch.

[0029] Step 3, final refining and sulfur addition: Adjust the roll gap of the open mill to 1 mm, put the mixed masterbatch into the open mill for thin passing 2 times, discharge the material, adjust the roll gap of the open mill to 1.5 mm, add the accelerator and sulfur, make 3 triangular bales, after discharging the material, adjust the roll gap to 5.0 mm again, perform left and right 3 / 4 cut rubber 2 times, and take off the sheet.

[0030] The third object of the present invention is to provide a rubber composite material with both high heat resistance and radiation resistance. Specifically, the raw material composition of the rubber composite material is to add a radiation-resistant auxiliary agent and a silane coupling agent on the basis of the raw materials of the highly heat-resistant rubber composite material described in claim 1.

[0031] Further defined, the addition amount of the radiation-resistant auxiliary agent is 30 to 50 parts.

[0032] Further defined, the radiation-resistant auxiliary agent is one or a mixture of more than one of lead oxide, bismuth oxide, barium sulfate, and antimony trioxide.

[0033] Further defined, the addition amount of the silane coupling agent is 0.5 to 10 parts.

[0034] Further defined, the silane coupling agent is bis-[γ-(triethoxysilyl)propyl]tetrasulfide or bis-3-(triethoxysilylpropyl)-disulfide.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] (1) The present invention significantly improves the heat resistance of the rubber composite material by introducing an iron-based catalyzed butadiene-pentadiene rubber with a high content of vinyl and propylene side groups into the rubber composite material. As the amount of the iron-based catalyzed butadiene-pentadiene rubber added increases from 40 parts to 80 parts, the heat resistance of the rubber composite material continues to improve. After exceeding 80 parts, the rubber rebound performance decreases significantly.

[0037] (2) The iron-based catalyzed butadiene-pentadiene rubber molecular chain introduced into the rubber composite material by the present invention has a relatively large number of 1,2-butadiene and 3,4-isoprene structural units, the main chain double bond content of the rubber molecular chain is low and the side group vinyl and propylene content is high. Since vinyl and propylene are electron-withdrawing groups, the reaction activity of the main chain of the rubber molecular chain can be reduced, and the heat resistance of the iron-based catalyzed butadiene-pentadiene rubber can be effectively improved. At the same time, the iron-based catalyzed butadiene-pentadiene rubber structure has a high content of tertiary carbon atoms, and the carbon free radicals formed by the breaking of weak bonds during the heating process can continue to cross-link, thereby effectively avoiding the problem of molecular chain breakage due to heat, and better improving the heat resistance and radiation resistance of the rubber composite material.

[0038] (3) Due to the presence of 1,4-butadiene and 1,4-isoprene, the iron-based catalyzed butadiene-pentadiene rubber introduced into the rubber composite material of the present invention has double bonds in the main chain, which, on the one hand, helps to ensure the vulcanization speed of the rubber composite material, and on the other hand, can make the molecular chain have a certain flexibility, thereby ensuring a certain resilience of the rubber composite material.

[0039] (4) The iron-based catalyzed butyl-ethylene rubber introduced into the rubber composite material by the present invention has 30% to 50% 1,4-isoprene structural units and 40% to 60% 1,4-butadiene structural units in its molecular chain, which have certain structural similarities with natural rubber, styrene rubber and styrene-butadiene rubber. Therefore, during the mixing process, the compatibility between different rubbers is relatively high. After vulcanization and cross-linking, the molecular chain segments are entangled and combined with each other, which can maximize the advantageous characteristics of each type of rubber and have a significant synergistic effect. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0041] The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, methods and instruments used are conventional materials, reagents, methods and instruments in the art unless otherwise specified, and can be obtained through commercial channels by those skilled in the art.

[0042] The formulation compositions of the rubber composites in Examples 1 to 4 of the present invention are listed in Table 1, and the main properties of the rubber composites in Examples 1 to 4 are listed in Table 2. The formulation compositions of the rubber composites in Examples 5 to 8 of the present invention are listed in Table 3, and the main properties of the rubber composites in Examples 5 to 8 are listed in Table 4.

[0043] Example 1:

[0044] The raw material ratio of the high heat-resistant rubber composite in this example is as shown in the data corresponding to Example 1 in Table 1;

[0045] Among them, the molecular weight of the butadiene-pentene rubber is 485,000, the glass transition temperature is -22 °C, and the content of vinyl and propenyl side groups is 58%; the butadiene-pentene rubber is prepared by coordination polymerization using an iron-based catalyst. During the preparation process, the molar ratio of monomer butadiene to isoprene is 1:1; the iron-based butadiene-pentene rubber is composed of 3,4-isoprene, 1,4-isoprene, 1,2-butadiene and 1,4-butadiene structural units; among them, the molar content of 1,2-butadiene is 48%, and the total molar content of cis-1,4-butadiene and trans-1,4-butadiene is 52%; the molar content of 3,4-isoprene is 68%, and the total molar content of cis-1,4-isoprene and trans-1,4-isoprene is 32%.

[0046] The method for preparing the high heat-resistant rubber composite of Example 1 is carried out according to the following steps:

[0047] Step 1, rubber plasticizing: In an internal mixer, the filling coefficient is 0.7 ± 0.02. Add natural rubber and butadiene-pentene rubber for plasticizing. The plasticizing temperature is 120 ± 5 °C, and the plasticizing time is 180 s. After plasticizing, obtain plasticized rubber;

[0048] Step 2, masterbatch mixing: In an internal mixer, the filling coefficient is 0.7 ± 0.02. Put the plasticized rubber parked for more than 4 h, reinforcing filler, activator and antioxidant into the internal mixer for mixing. The mixing temperature is 145 °C ± 5 °C, and the mixing time is 280 s. After mixing, obtain a mixed masterbatch;

[0049] Step 3, final refining and vulcanization: Adjust the roll gap of the open mill to 1 mm. Put the mixed masterbatch into the open mill for two passes of thin passing, discharge the material, adjust the roll gap of the open mill to 1.5 mm, add accelerator and sulfur, make three triangular packages, discharge the material, then adjust the roll gap to 5.0 mm, perform left and right 3 / 4 cuttings twice, and take off the sheet.

[0050] Example 2:

[0051] The raw material ratio of the high heat-resistant rubber composite in this example is as shown in the data corresponding to Example 2 in Table 1;

[0052] Among them, the molecular weight of the butadiene-isoprene rubber is 463,000, the glass transition temperature is -24 °C, and the content of vinyl and propenyl side groups is 55%; the butadiene-isoprene rubber is prepared by coordination polymerization using an iron-based catalyst. During the preparation process, the molar ratio of monomer butadiene to isoprene is 1:1; the iron-based butadiene-isoprene rubber is composed of 3,4-isoprene, 1,4-isoprene, 1,2-butadiene, and 1,4-butadiene structural units; among them, the molar content of 1,2-butadiene is 44%, and the total molar content of cis-1,4-butadiene and trans-1,4-butadiene is 56%; the molar content of 3,4-isoprene is 66%, and the total molar content of cis-1,4-isoprene and trans-1,4-isoprene is 34%.

[0053] The method for preparing the high heat-resistant rubber composite of Preparation Example 2 is carried out according to the following steps:

[0054] Step 1, rubber plasticizing: In an internal mixer, the filling coefficient is 0.7 ± 0.02. Add natural rubber and butadiene-isoprene rubber for plasticizing. The plasticizing temperature is 125 ± 5 °C, and the plasticizing time is 180 s. After plasticizing, obtain the plasticized rubber;

[0055] Step 2, masterbatch mixing: In an internal mixer, the filling coefficient is 0.7 ± 0.02. Put the plasticized rubber parked for more than 4 h, reinforcing filler, activator, and antioxidant into the internal mixer for mixing. The mixing temperature is 145 °C ± 5 °C, and the mixing time is 280 s. After mixing, obtain the mixed masterbatch;

[0056] Step 3, final vulcanization: Adjust the roll gap of the open mill to 1 mm. Put the mixed masterbatch into the open mill and thin-pass it 2 times, then discharge. Adjust the roll gap of the open mill to 1.5 mm, add accelerator and sulfur, make 3 triangular bales, discharge, then adjust the roll gap to 5.0 mm, and perform left and right 3 / 4 cut-gumming 2 times, then take off the sheet.

[0057] Example 3:

[0058] The raw material ratio of the high heat-resistant rubber composite of this example is as shown in the corresponding data of Example 3 in Table 1;

[0059] Among them, the molecular weight of the butadiene-isoprene rubber is 426,000, the glass transition temperature is -28°C, and the content of vinyl and propenyl side groups is 52.5%; the butadiene-isoprene rubber is prepared by coordination polymerization using an iron-based catalyst. During the preparation process, the molar ratio of monomer butadiene to isoprene is 1:1; the iron-based butadiene-isoprene rubber is composed of 3,4-isoprene, 1,4-isoprene, 1,2-butadiene, and 1,4-butadiene structural units; among them, the molar content of 1,2-butadiene is 45%, and the total molar content of cis-1,4-butadiene and trans-1,4-butadiene is 55%; the molar content of 3,4-isoprene is 60%, and the total molar content of cis-1,4-isoprene and trans-1,4-isoprene is 40%.

[0060] The method for preparing the high heat-resistant rubber composite of Preparation Example 3 is carried out according to the following steps:

[0061] Step 1, rubber plasticizing: In an internal mixer, the filling coefficient is 0.7 ± 0.02. Add natural rubber and butadiene-isoprene rubber for plasticizing. The plasticizing temperature is 125 ± 5°C, and the plasticizing time is 180 s. After plasticizing, obtain the plasticized rubber;

[0062] Step 2, masterbatch mixing: In an internal mixer, the filling coefficient is 0.7 ± 0.02. Put the plasticized rubber parked for more than 4 h, reinforcing filler, activator, and antioxidant into the internal mixer for mixing. The mixing temperature is 145°C ± 5°C, and the mixing time is 280 s. After mixing, obtain the mixed masterbatch;

[0063] Step 3, final vulcanization: Adjust the roll gap of the open mill to 1 mm. Put the mixed masterbatch into the open mill for thin passing 2 times, discharge the material. Adjust the roll gap of the open mill to 1.5 mm, add accelerator and sulfur, make 3 triangular packages, discharge the material, then adjust the roll gap to 5.0 mm, perform left and right 3 / 4 cutting and rubberizing 2 times, and take off the sheet.

[0064] Example 4:

[0065] The raw material ratio of the high heat-resistant rubber composite of this example is as shown in the data corresponding to Example 4 in Table 1;

[0066] Among them, the molecular weight of the butyl-pentyl rubber is 588,000, the glass transition temperature is -15°C, and the content of vinyl and propenyl side groups is 54%; the butyl-pentyl rubber is prepared by coordination polymerization using an iron-based catalyst. During the preparation process, the molar ratio of monomer butadiene to isoprene is 1:1; the iron-based butyl-pentyl rubber is composed of 3,4-isoprene, 1,4-isoprene, 1,2-butadiene, and 1,4-butadiene structural units; among them, the molar content of 1,2-butadiene is 49%, and the total molar content of cis-1,4-butadiene and trans-1,4-butadiene is 51%; the molar content of 3,4-isoprene is 59%, and the total molar content of cis-1,4-isoprene and trans-1,4-isoprene is 41%.

[0067] The method for preparing the high heat-resistant rubber composite of Preparation Example 4 is carried out according to the following steps:

[0068] Step 1, rubber plasticizing: In an internal mixer, with a filling coefficient of 0.7 ± 0.02, natural rubber and butyl-pentyl rubber are added for plasticizing. The plasticizing temperature is 125 ± 5°C, and the plasticizing time is 180 s. After plasticizing, plasticized rubber is obtained;

[0069] Step 2, masterbatch mixing: In an internal mixer, with a filling coefficient of 0.7 ± 0.02, the plasticized rubber parked for more than 4 h, reinforcing filler, activator, and antioxidant are put into the internal mixer for mixing. The mixing temperature is 145°C ± 5°C, and the mixing time is 280 s. After mixing, the mixed masterbatch is obtained;

[0070] Step 3, final refining and vulcanization: Adjust the roll gap of the open mill to 1 mm, put the mixed masterbatch into the open mill for two passes of thin passing, discharge the material, adjust the roll gap of the open mill to 1.5 mm, add accelerator and sulfur, make three triangular packages, after discharging the material, adjust the roll gap to 5.0 mm again, perform two passes of left and right 3 / 4 cut rubber, and take off the sheet.

[0071] Comparative Example 1:

[0072] The formula of the rubber composite of this comparative example is shown in the data corresponding to Comparative Example 1 in Table 1; the types of its raw materials and the preparation method are the same as those of Example 4.

[0073] Comparative Example 2:

[0074] The formula of the rubber composite of this comparative example is shown in the data corresponding to Comparative Example 2 in Table 1; the types of its raw materials and the preparation method are the same as those of Example 3.

[0075] Comparative Example 3:

[0076] The formula of the rubber composite of this comparative example is shown in the data corresponding to Comparative Example 3 in Table 1; the types of its raw materials and the preparation method are the same as those of Example 3.

[0077] Table 1 Composition table of rubber composites

[0078]

[0079] Table 2 Main properties of the rubber composite

[0080]

[0081]

[0082] As can be seen from Table 2, by comparing Example 3 with Comparative Examples 2-3, it can be analyzed that after the heat resistance experiment at 130 °C for 72 h, the aging rate of Example 3 is significantly lower than that of the comparative examples. This proves that the addition of iron-catalyzed butadiene-isoprene rubber endows the rubber composite with good resilience, mechanical properties and vulcanization rate, and also has excellent heat resistance. This is mainly because on the one hand, there are more 1,2-butadiene and 3,4-isoprene structural units in the molecular chain of iron-catalyzed butadiene-isoprene rubber. The content of double bonds in the main chain of the rubber molecular chain is low, while the content of side vinyl and propenyl groups is high. Vinyl and propenyl are electron-withdrawing groups, which can reduce the reaction activity of the main chain of the rubber molecular chain and effectively improve the heat resistance of iron-catalyzed butadiene-isoprene rubber; on the other hand, the content of tertiary carbon atoms in the structure of iron-catalyzed butadiene-isoprene rubber is high. The carbon free radicals formed by the cleavage of weak bonds during heating can continue to crosslink, thus effectively avoiding the problem of molecular chain breakage during heating and better improving the heat resistance of the rubber composite.

[0083] By comparing Examples 1-4 with Comparative Examples 2-3, it can be analyzed that the optimal vulcanization time, scorch time, vulcanization rate index and resilience of Example 4 are all better than those of the comparative examples. This is mainly because the presence of 1,4-butadiene and 1,4-isoprene in iron-catalyzed butadiene-isoprene rubber. On the one hand, the double bonds contained in the main chain are beneficial to ensure the vulcanization speed of the rubber composite, and on the other hand, they can make the molecular chain have a certain flexibility, ensuring a certain resilience of the rubber composite.

[0084] By comparing Examples 1-4 with Comparative Example 1, it can be seen that after the addition amount of iron-catalyzed butadiene-isoprene rubber exceeds 80 parts, the resilience performance drops significantly. This is mainly because the side group content is too high, the side group volume is large, the steric hindrance is high, the molecular chain flexibility decreases, and it is difficult to change the molecular chain conformation under stress, resulting in a decrease in the resilience of the rubber composite.

[0085] Example 5:

[0086] The formula of the rubber composite with both high heat resistance and radiation resistance in this example is shown in the data corresponding to Example 5 in Table 3;

[0087] Among them, the molecular weight of the butadiene-isoprene rubber is 525,000, the glass transition temperature is -22 °C, and the content of vinyl and propenyl side groups is 58%; the butadiene-isoprene rubber is prepared by coordination polymerization using an iron-based catalyst. During the preparation process, the molar ratio of monomer butadiene to isoprene is 1:1; the iron-based butadiene-isoprene rubber is composed of 3,4-isoprene, 1,4-isoprene, 1,2-butadiene, and 1,4-butadiene structural units; among them, the molar content of 1,2-butadiene is 48%, and the total molar content of cis-1,4-butadiene and trans-1,4-butadiene is 52%; the molar content of 3,4-isoprene is 68%, and the total molar content of cis-1,4-isoprene and trans-1,4-isoprene is 32%.

[0088] The method for preparing the high heat-resistant rubber composite of Preparation Example 5 is carried out according to the following steps:

[0089] Step 1, rubber plasticizing: In an internal mixer, with a filling coefficient of 0.7 ± 0.02, natural rubber and butadiene-isoprene rubber are added for plasticizing. The plasticizing temperature is 120 ± 5 °C, and the plasticizing time is 180 s. After plasticizing, plasticized rubber is obtained;

[0090] Step 2, masterbatch mixing: In an internal mixer, with a filling coefficient of 0.7 ± 0.02, the plasticized rubber parked for more than 4 h, reinforcing filler, activator, and antioxidant are put into the internal mixer for mixing. The mixing temperature is 145 °C ± 5 °C, and the mixing time is 280 s. After mixing, the mixed masterbatch is obtained;

[0091] Step 3, final vulcanization: Adjust the roll gap of the open mill to 1 mm, put the mixed masterbatch into the open mill for two thin passes, discharge the material, adjust the roll gap of the open mill to 1.5 mm, add accelerator and sulfur, make three triangular bales, discharge the material, then adjust the roll gap to 5.0 mm, and perform left and right 3 / 4 cuttings twice, and take off the sheet.

[0092] Example 6:

[0093] The formula of the rubber composite with both high heat resistance and radiation resistance in this example is shown in the data corresponding to Example 6 in Table 3;

[0094] Among them, the molecular weight of the butadiene-isoprene rubber is 593,000, the glass transition temperature is -24°C, and the content of vinyl and propenyl side groups is 55%; the butadiene-isoprene rubber is prepared by coordination polymerization using an iron-based catalyst. During the preparation process, the molar ratio of monomer butadiene to isoprene is 1:1; the iron-based butadiene-isoprene rubber is composed of 3,4-isoprene, 1,4-isoprene, 1,2-butadiene, and 1,4-butadiene structural units; among them, the molar content of 1,2-butadiene is 44%, and the total molar content of cis-1,4-butadiene and trans-1,4-butadiene is 56%; the molar content of 3,4-isoprene is 66%, and the total molar content of cis-1,4-isoprene and trans-1,4-isoprene is 34%.

[0095] The method for preparing the high heat-resistant rubber composite of Preparation Example 6 is carried out according to the following steps:

[0096] Step 1, rubber plasticizing: In an internal mixer, the filling coefficient is 0.7 ± 0.02. Add natural rubber and butadiene-isoprene rubber for plasticizing. The plasticizing temperature is 125 ± 5°C, and the plasticizing time is 180 s. After plasticizing, obtain the plasticized rubber;

[0097] Step 2, masterbatch mixing: In an internal mixer, the filling coefficient is 0.7 ± 0.02. Put the plasticized rubber parked for more than 4 h, reinforcing filler, activator, and antioxidant into the internal mixer for mixing. The mixing temperature is 145°C ± 5°C, and the mixing time is 280 s. After mixing, obtain the mixed masterbatch;

[0098] Step 3, final refining and vulcanization: Adjust the roll gap of the open mill to 1 mm. Put the mixed masterbatch into the open mill for two passes of thin passing, discharge the material. Adjust the roll gap of the open mill to 1.5 mm, add accelerator and sulfur, make three triangular bales, discharge the material, then adjust the roll gap to 5.0 mm, and perform two passes of left and right 3 / 4 cut rubber, and take off the sheet.

[0099] Example 7:

[0100] The formulation of the rubber composite with both high heat resistance and radiation resistance in this example is shown in the data corresponding to Example 7 in Table 3;

[0101] Among them, the molecular weight of the butadiene-isoprene rubber is 603,000, the glass transition temperature is -28 °C, and the content of vinyl and propenyl side groups is 52.5%; the butadiene-isoprene rubber is prepared by coordination polymerization using an iron-based catalyst. During the preparation process, the molar ratio of monomer butadiene to isoprene is 1:1; the iron-based butadiene-isoprene rubber is composed of 3,4-isoprene, 1,4-isoprene, 1,2-butadiene, and 1,4-butadiene structural units; among them, the molar content of 1,2-butadiene is 45%, and the total molar content of cis-1,4-butadiene and trans-1,4-butadiene is 55%; the molar content of 3,4-isoprene is 60%, and the total molar content of cis-1,4-isoprene and trans-1,4-isoprene is 40%.

[0102] The method for preparing the high heat-resistant rubber composite of Preparation Example 7 is carried out according to the following steps:

[0103] Step 1, rubber plasticizing: In an internal mixer, the filling coefficient is 0.7 ± 0.02. Add natural rubber and butadiene-isoprene rubber for plasticizing. The plasticizing temperature is 125 ± 5 °C, and the plasticizing time is 180 s. After plasticizing, obtain the plasticized rubber;

[0104] Step 2, masterbatch mixing: In an internal mixer, the filling coefficient is 0.7 ± 0.02. Put the plasticized rubber that has been parked for more than 4 h, reinforcing filler, activator, and antioxidant into the internal mixer for mixing. The mixing temperature is 145 °C ± 5 °C, and the mixing time is 280 s. After mixing, obtain the mixed masterbatch;

[0105] Step 3, final vulcanization: Adjust the roll gap of the open mill to 1 mm. Put the mixed masterbatch into the open mill and thin it twice, then discharge. Adjust the roll gap of the open mill to 1.5 mm, add accelerator and sulfur, make 3 triangular packages, discharge, and then adjust the roll gap to 5.0 mm, and perform left and right 3 / 4 cut rubber twice, then take off the sheet.

[0106] Example 8:

[0107] The formula of the rubber composite with both high heat resistance and radiation resistance in this example is shown in the data corresponding to Example 8 in Table 3;

[0108] Among them, the molecular weight of the butadiene-isoprene rubber is 688,000, the glass transition temperature is -15°C, and the content of vinyl and propenyl side groups is 54%; the butadiene-isoprene rubber is prepared by coordination polymerization using an iron-based catalyst. During the preparation process, the molar ratio of monomer butadiene to isoprene is 1:1; the iron-based butadiene-isoprene rubber is composed of 3,4-isoprene, 1,4-isoprene, 1,2-butadiene, and 1,4-butadiene structural units; among them, the molar content of 1,2-butadiene is 49%, and the total molar content of cis-1,4-butadiene and trans-1,4-butadiene is 51%; the molar content of 3,4-isoprene is 59%, and the total molar content of cis-1,4-isoprene and trans-1,4-isoprene is 41%.

[0109] The method for preparing the high heat-resistant rubber composite of Preparation Example 8 is carried out according to the following steps:

[0110] Step 1, rubber plasticizing: In an internal mixer, the filling coefficient is 0.7 ± 0.02, natural rubber and butadiene-isoprene rubber are added for plasticizing, the plasticizing temperature is 125 ± 5°C, and the plasticizing time is 180 s. After plasticizing, plasticized rubber is obtained;

[0111] Step 2, masterbatch mixing: In an internal mixer, the filling coefficient is 0.7 ± 0.02, the plasticized rubber parked for more than 4 h, reinforcing filler, activator, and antioxidant are put into the internal mixer for mixing. The mixing temperature is 145°C ± 5°C, and the mixing time is 280 s. After mixing, the mixed masterbatch is obtained;

[0112] Step 3, final refining and sulfur addition: Adjust the roll gap of the open mill to 1 mm, put the mixed masterbatch into the open mill for thin passing 2 times, discharge the material, adjust the roll gap of the open mill to 1.5 mm, add accelerator and sulfur, make 3 triangular packages, after discharging the material, adjust the roll gap to 5.0 mm again, perform left and right 3 / 4 cut rubber 2 times, and take off the sheet.

[0113] Comparative Example 4:

[0114] The formula of the rubber composite of this comparative example is shown in the data corresponding to Comparative Example 1 in Table 3; the types of its raw materials and the preparation method are the same as those of Example 8.

[0115] Comparative Example 5:

[0116] The formula of the rubber composite of this comparative example is shown in the data corresponding to Comparative Example 2 in Table 3; the types of its raw materials and the preparation method are the same as those of Example 7.

[0117] Comparative Example 6:

[0118] The formula of the rubber composite of this comparative example is shown in the data corresponding to Comparative Example 3 in Table 3; the types of its raw materials and the preparation method are the same as those of Example 7.

[0119] Table 3

[0120]

[0121]

[0122] Table 4

[0123] Performance parameters Example 5 Example 6 Example 7 Example 8 Comparative Example 4 Comparative Example 5 Comparative Example 6 Tensile strength, MPa 18.65 18.22 17.94 17.54 16.69 16.87 15.32 <![CDATA[10 7 radial tensile strength at 72 h, MPa]]> 19.77 19.25 18.85 18.14 17.05 16.14 13.66 <![CDATA[10 8 radial tensile strength at 72 h, MPa]]> 20.98 20.31 19.76 18.92 17.95 15.85 10.06 Elongation at break, % 537.25 525.74 506.96 478.41 442.62 457.41 556.74 <![CDATA[10 7 Elongation at break after 72 h of radiation, %]]> 525.11 514.48 496.28 470.55 439.25 426.08 495.46 <![CDATA[10 8 Elongation at break after 72 h of radiation, %]]> 506.11 499.48 484.22 461.85 430.35 405.66 418.63 Shore A hardness 61 62 62 62 65 62 56 <![CDATA[10 7 Shore A hardness after 72 h of radiation]]> 63 64 65 65 67 62 54 <![CDATA[10 8 Shore A hardness at 72 h 66 67 68 68 69 60 50 Optimal vulcanization time, min 9.30 9.68 9.89 10.07 11.70 13.70 12.84 Vulcanization rate index 16.53 15.94 15.67 15.50 13.00 10.63 11.64 Rebound rate 45.68 44.19 43.25 41.20 33.14 36.88 58.79

[0124] Analysis of the data in Table 4 shows that compared with Comparative Example 5 and Comparative Example 6, after a radiation resistance experiment of 10 8 rad for 72 h in Example 7, the aging rates are significantly lower than those in the comparative examples, proving that the iron-based catalytic butadiene-pentene rubber has excellent radiation resistance on the basis of good resilience, mechanical properties and vulcanization rate. This is mainly because on the one hand, there are more 1,2-butadiene and 3,4-isoprene structural units in the molecular chain of the iron-based catalytic butadiene-pentene rubber. The content of double bonds in the main chain of the rubber molecular chain is low while the content of side vinyl and propenyl groups is high. Vinyl and propenyl are electron-withdrawing groups, which can reduce the reaction activity of the main chain of the rubber molecular chain and effectively improve the radiation resistance of the iron-based catalytic butadiene-pentene rubber; on the other hand, the content of tertiary carbon atoms in the structure of the iron-based catalytic butadiene-pentene rubber is high. The carbon free radicals formed by the cleavage of weak bonds during heating can continue to crosslink, thus effectively avoiding the problem of molecular chain breakage during heating and better improving the radiation resistance of the rubber composite material.

[0125] Secondly, 30%-50% of the 1,4-isoprene structural units and 40%-60% of the 1,4-butadiene structural units in the molecular chain of the iron-based catalytic butadiene-pentene rubber have a certain structural similarity with natural rubber, cis-polybutadiene rubber and styrene-butadiene rubber. Therefore, during the mixing process, the compatibility between different rubbers is relatively high. After vulcanization crosslinking, the molecular chain segments are entangled and combined with each other to form a quasi-homogeneous structure of "you have me in you and I have you in me", which can maximize the advantage characteristics of each rubber type and the synergistic effect is obvious.

[0126] Compared with Comparative Example 5 and Comparative Example 6, the optimal vulcanization time, scorch time, vulcanization rate index and resilience of Examples 5-8 are all better than those of the comparative examples. Due to the presence of 1,4-butadiene and 1,4-isoprene in the iron-based catalytic butadiene-pentene rubber, on the one hand, the double bonds contained in the main chain are beneficial to ensuring the vulcanization speed of the rubber composite material, and on the other hand, they can make the molecular chain have a certain flexibility, ensuring a certain resilience of the rubber composite material.

[0127] It can be seen from the comparison between Examples 5-8 and Comparative Example 4 that when the addition amount of iron-based catalytic butadiene-pentene rubber exceeds 80 parts, the resilience performance drops significantly. This is mainly because the content of side groups is too high, the side group volume is large, the steric hindrance is high, the flexibility of the molecular chain decreases, and under the action of stress, it is difficult for the chain movement to change the molecular chain conformation, resulting in a decrease in the resilience of the rubber composite material.

[0128] By comparing the samples provided by the present invention with the comparative samples in the above examples, it can be seen that a radiation-resistant iron-based catalytic butadiene-pentene rubber provided by the present invention has excellent radiation resistance on the basis of good resilience, mechanical properties and vulcanization rate.

[0129] As described in the above embodiments, it is only for clearly explaining the specific implementation manners and not a limitation on the implementation manners. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claimed rights.

Claims

1. A high heat-resistant rubber composite material, characterized in that, It consists of the following raw materials in parts by weight: 100 parts of olefin rubber; 10 - 50 parts of plasticizer; 20 - 80 parts of reinforcing filler; 1 - 10 parts of activator; 1 - 4 parts of vulcanizing agent; 1 - 5 parts of accelerator; 1 - 5 parts of antioxidant; Among them, the olefin rubber is composed of 30 - 60 parts of natural rubber and 40 - 70 parts of butenyl rubber in parts by weight. The molecular weight of the butenyl rubber is 50 - 80w, the Tg is -30°C to -10°C, and the side group content is 40% - 70%.

2. The high heat-resistant rubber composite material according to claim 1, wherein The butenyl rubber is prepared by coordinative polymerization of monomer isoprene and monomer butadiene using an iron-based catalyst. The molar ratio of monomer butadiene to isoprene is 1:1 during the preparation process.

3. The high heat-resistant rubber composite material according to claim 1, characterized in that, The butenyl rubber is composed of 3,4-isoprene, 1,4-isoprene, 1,2-butadiene and 1,4-butadiene structural units.

4. The high heat-resistant rubber composite material according to claim 3, wherein The molar content of 1,2-butadiene is 40% - 60%, and the total molar content of cis-1,4-butadiene and trans-1,4-butadiene is 40% - 60%; the molar content of 3,4-isoprene is 50% - 70%, and the total molar content of cis-1,4-isoprene and trans-1,4-isoprene is 30% - 50%.

5. The high heat-resistant rubber composite material according to claim 1, wherein The plasticizer is one or a mixture of paraffin oil, aromatic oil, petrolatum, petroleum asphalt and transformer oil.

6. The high heat-resistant rubber composite material according to claim 1, wherein The reinforcing filler is one or a mixture of carbon black, white carbon black, fumed silica, calcium carbonate, mica powder, hard kaolin, barium sulfate, magnesium sulfate, asbestos powder.

7. The high heat-resistant rubber composite material according to claim 1, wherein The activator is zinc oxide and stearic acid, where the addition amount of zinc oxide is 0.5 - 5 parts, and the addition amount of stearic acid is 0.5 - 5 parts.

8. The high heat-resistant rubber composite material according to claim 1, wherein The vulcanizing agent is one or a mixture of phenolic resin, dicumyl peroxide, sulfur, etc.; the accelerator is one or a mixture of sulfenamide vulcanization accelerators, thiazole vulcanization accelerators, thiuram vulcanization accelerators, guanidine vulcanization accelerators, etc.; the antioxidant is one or a mixture of antioxidant RD, antioxidant D, antioxidant 4020, antioxidant A, antioxidant MB, thio-dinaphthol, etc.

9. A method for preparing the high heat-resistant rubber composite material according to claim 1, characterized in that, It is prepared by a method of stage mixing.

10. A rubber composite material with radiation resistance, characterized in that, The raw material composition of this rubber composite material is based on the raw materials of the high heat-resistant rubber composite material described in claim 1, with the addition of radiation-resistant additives and silane coupling agents.

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