A process for preparing a blowout preventer rubber core with excellent corrosion resistance

Abstract

The present application relates to the field of rubber, and specifically discloses a process for preparing a blowout preventer rubber core with excellent corrosion resistance. A method for preparing a blowout preventer rubber core with excellent corrosion resistance is as follows: weighing nitrile latex and stirring; adding deionized water and stirring, and then adding a defoaming agent; adding anhydrous copper sulfate, sodium lauryl sulfate and hydrazine hydrate in sequence; adding hydrogen peroxide, and after the hydrogen peroxide is completely added, continuing the reaction to obtain hydrogenated nitrile latex; placing the hydrogenated nitrile latex in a water bath environment, adding calcium chloride solution to obtain flocculated hydrogenated nitrile rubber; soaking the flocculated hydrogenated nitrile rubber in deionized water, taking it out and drying it to obtain hydrogenated nitrile rubber; completely immersing the hydrogenated nitrile rubber in a polydimethylsiloxane solution, taking it out after soaking and hanging it in a ventilated place to dry, and then placing it in an oven for curing to obtain modified hydrogenated nitrile rubber. The blowout preventer rubber core with excellent corrosion resistance of the present application has the advantage of excellent corrosion resistance.

Description

Technical Field

[0001] The present application relates to the field of rubber technology, and more specifically, to a process for preparing a blowout preventer rubber core with excellent corrosion resistance. Background Art

[0002] A blowout preventer is a device used to close the wellhead and prevent blowout accidents during operations such as oil testing, well repair and completion. It has the characteristics of simple structure, easy operation and high pressure resistance. It is a safety sealing wellhead device commonly used in oil fields to prevent blowouts. The key component inside the blowout preventer when in use is the rubber core. During use, the rubber core is restricted by the top cover and cannot move upward. Under the action of the inner cone surface of the piston, it is forced to squeeze and shrink toward the center of the wellbore until the hollow part of the rubber core is filled with rubber, thereby achieving the purpose of fully sealing the wellhead.

[0003] As oil exploration drilling becomes deeper and deeper, more and more oil and gas wells containing hydrogen sulfide are discovered. Hydrogen sulfide is corrosive, so in order to prevent the rubber core from being corroded by hydrogen sulfide, hydrogenated nitrile rubber is usually used. Hydrogenated nitrile rubber is a heat-resistant and oil-resistant elastomer made by hydrogenating nitrile rubber. Since the molecular structure of hydrogenated nitrile rubber contains fewer or no carbon-carbon double bonds, it not only has the oil resistance and wear resistance of nitrile rubber, but also has improved weather resistance and chemical stability compared to nitrile rubber. In addition, it has higher strength that most oil-resistant rubbers do not have. In particular, its high temperature resistance is greatly improved compared to nitrile rubber. However, the excessive content of acrylonitrile groups in hydrogenated nitrile rubber will also react with hydrogen sulfide to form thioamides, which will cause aging and degradation of hydrogenated nitrile rubber, thereby affecting the corrosion resistance of hydrogenated nitrile rubber. Summary of the Invention

[0004] In order to improve the defect that the corrosion resistance of hydrogenated nitrile rubber is still insufficient, the present application provides a process for preparing a blowout preventer rubber core with excellent corrosion resistance.

[0005] This application provides a blowout preventer rubber core with excellent corrosion resistance, which adopts the following technical solutions:

[0006] A process for preparing a blowout preventer rubber core with excellent corrosion resistance comprises the following steps:

[0007] S1: Weigh nitrile latex and stir;

[0008] S2: Add deionized water and stir, then add defoamer;

[0009] S3: adding anhydrous copper sulfate, sodium lauryl sulfate, and hydrazine hydrate in sequence;

[0010] S4: adding hydrogen peroxide dropwise, and after the hydrogen peroxide is completely added, the reaction is continued to obtain hydrogenated nitrile latex;

[0011] S5: placing the hydrogenated nitrile butadiene rubber latex in a water bath environment and adding a calcium chloride solution to obtain flocculated hydrogenated nitrile butadiene rubber;

[0012] S6: soaking the flocculated hydrogenated nitrile rubber in deionized water, taking it out and drying it to obtain hydrogenated nitrile rubber;

[0013] S7: Immerse the hydrogenated nitrile rubber completely in the polydimethylsiloxane solution, take it out after soaking, hang it in a ventilated place to dry, and then place it in an oven for curing to obtain modified hydrogenated nitrile rubber.

[0014] Since hydrogenated nitrile rubber is obtained by hydrogenating the double bonds in nitrile rubber, this hydrogenation process reduces the unsaturated bonds in the molecule, thereby reducing the possibility of reaction with hydrogen sulfide. Hydrogenated nitrile rubber has good heat resistance and can maintain its physical and chemical properties at higher temperatures. At the same time, hydrogenated nitrile rubber also has excellent tear and wear resistance, which makes it more reliable when used in corrosive environments.

[0015] However, the acrylonitrile group in hydrogenated nitrile rubber is a polar functional group containing a carbon-nitrogen triple bond and has certain chemical reactivity. During oil exploration, the acrylonitrile group will react with hydrogen sulfide to form thioamide, thereby accelerating the aging and degradation of the hydrogenated nitrile rubber and causing the corrosion resistance of the hydrogenated nitrile rubber to decline. Since the polydimethylsiloxane solution used in this application contains polydimethylsiloxane, the acrylonitrile group can react to form a cross-linked structure in the polydimethylsiloxane. This cross-linking occurs not only between the acrylonitrile groups, but also between the acrylonitrile groups and the siloxy chains of the polydimethylsiloxane, thereby forming a dense network structure on the surface of the hydrogenated nitrile rubber, making it difficult for hydrogen sulfide to enter the hydrogenated nitrile rubber and react with the acrylonitrile groups, thereby improving the corrosion resistance of the hydrogenated nitrile rubber.

[0016] Preferably, a process for preparing a blowout preventer rubber core with excellent corrosion resistance comprises the following steps:

[0017] S1: Weigh 148g-152g of nitrile latex with a solid content of 15%-19% and an acrylonitrile content of 32%-34% and stir;

[0018] S2: Add 297g-303g of deionized water and stir, then add 5-10ml of defoamer;

[0019] S3: Add 0.005g-0.011g of anhydrous copper sulfate, 0.13g-0.17g of sodium lauryl sulfate, and 225g-233g of hydrazine hydrate in sequence;

[0020] S4: Add 95g-101g of hydrogen peroxide dropwise. After the hydrogen peroxide is completely added, continue the reaction for 0.5h-1.5h to obtain hydrogenated nitrile latex;

[0021] S5: placing the hydrogenated nitrile butadiene rubber latex in a water bath at 3-7°C, adding 5 g-5.8 g of a 19%-21% calcium chloride solution to obtain flocculated hydrogenated nitrile butadiene rubber;

[0022] S6: Soaking the flocculated hydrogenated nitrile rubber in deionized water for 22-26 hours, taking it out and drying it to obtain hydrogenated nitrile rubber;

[0023] S7: Immerse the hydrogenated nitrile rubber completely in 136g-140g of polydimethylsiloxane solution for 1h-2h, then take it out and hang it in a ventilated place to dry, and then place it in a 55-65°C oven to cure for 23-25h to obtain modified hydrogenated nitrile rubber.

[0024] Preferably, the polydimethylsiloxane solution comprises the following raw materials: vinyl terminated RTV-615 prepolymer and n-hexane.

[0025] Since acrylonitrile contains polar cyano groups, it can form weak interactions with oils and other non-polar solvents, reducing the absorption of these substances, thereby giving hydrogenated nitrile rubber good oil resistance and chemical resistance. However, acrylonitrile has certain chemical reactivity and there is a possibility of reacting with hydrogen sulfide to a certain extent. The vinyl-terminated RTV-615 prepolymer contains double bonds and can be used as a cross-linking agent. Therefore, the double bonds of the vinyl-terminated RTV-615 prepolymer can react with acrylonitrile to form a cross-linked network.

[0026] Preferably, the polydimethylsiloxane solution comprises 9.8 g to 12.2 g of vinyl terminated RTV-615 prepolymer and 124.5 to 128.5 g of n-hexane.

[0027] The amount of vinyl-terminated RTV-615 prepolymer directly affects the crosslinking density of hydrogenated nitrile rubber. Therefore, an appropriate amount of vinyl-terminated RTV-615 prepolymer can make the hydrogenated nitrile rubber have an appropriate crosslinking structure.

[0028] Preferably, the vinyl terminated RTV-615 prepolymer is MOMENTIVE RTV-615 prepolymer.

[0029] Preferably, the vinyl terminated RTV-615 type prepolymer comprises a prepolymer RTV615-A and a crosslinker RTV615-B.

[0030] Since the prepolymer RTV615-A serves as a base polymer and provides a siloxane main chain, the heat resistance and resistance of the hydrogenated nitrile rubber are improved, while the crosslinker RTV615-B can react with the vinyl groups in the prepolymer RTV615-A to form crosslinking points, thereby increasing the crosslinking density of the hydrogenated nitrile rubber.

[0031] Preferably, the vinyl terminated RTV-615 prepolymer comprises 9g-11g of prepolymer RTV615-A and 0.8g-1.2g of crosslinker RTV615-B.

[0032] Preferably, the polydimethylsiloxane solution is prepared by fully mixing 9g-11g of RTV615-A and 0.8g-1.2g of RTV615-B, adding 124.5-128.5g of n-hexane to a polydimethylsiloxane solution with a mass fraction of 7-9%, and reacting for 22-26h.

[0033] Preferably, the mass ratio of the prepolymer RTV615-A to the crosslinker RTV615-B is 10:1.

[0034] Since an appropriate amount of crosslinker RTV615-B can effectively crosslink with the vinyl groups in the prepolymer RTV615-A to form a stable network structure, a mass ratio of 10:1 is beneficial to the crosslinking network of hydrogenated nitrile rubber, and an appropriate crosslinking density helps improve the chemical resistance of hydrogenated nitrile rubber, making hydrogenated nitrile rubber suitable for more harsh environments.

[0035] In summary, this application has the following beneficial effects:

[0036] 1. Since hydrogenated nitrile rubber is obtained by hydrogenating the double bonds in nitrile rubber, this hydrogenation process reduces the unsaturated bonds in the molecule, thereby reducing the possibility of reaction with hydrogen sulfide. In addition, hydrogenated nitrile rubber has good heat resistance and can maintain its physical and chemical properties at higher temperatures. At the same time, hydrogenated nitrile rubber also has excellent tear resistance and wear resistance, which makes it more reliable when used in corrosive environments.

[0037] However, the acrylonitrile group in hydrogenated nitrile rubber is a polar functional group containing a carbon-nitrogen triple bond and has certain chemical reactivity. During oil exploration, the acrylonitrile group will react with hydrogen sulfide to form thioamide, thereby accelerating the aging and degradation of the hydrogenated nitrile rubber and causing the corrosion resistance of the hydrogenated nitrile rubber to decline. Since the polydimethylsiloxane solution used in this application contains polydimethylsiloxane, the acrylonitrile group can react to form a cross-linked structure in the polydimethylsiloxane. This cross-linking occurs not only between the acrylonitrile groups, but also between the acrylonitrile groups and the siloxy chains of the polydimethylsiloxane, thereby forming a dense network structure on the surface of the hydrogenated nitrile rubber, making it difficult for hydrogen sulfide to enter the hydrogenated nitrile rubber and react with the acrylonitrile groups, thereby improving the corrosion resistance of the hydrogenated nitrile rubber.

[0038] 2. Since acrylonitrile contains polar cyano groups, it can form weak interactions with oils and other non-polar solvents, reducing the absorption of these substances, thereby giving hydrogenated nitrile rubber good oil resistance and chemical resistance. However, acrylonitrile has certain chemical reactivity and there is a possibility of reacting with hydrogen sulfide to a certain extent. The vinyl-terminated RTV-615 prepolymer contains double bonds and can be used as a cross-linking agent. Therefore, the double bonds of the vinyl-terminated RTV-615 prepolymer can react with acrylonitrile to form a cross-linked network.

[0039] 3. The amount of vinyl-terminated RTV-615 prepolymer directly affects the crosslinking density of hydrogenated nitrile rubber. Therefore, an appropriate amount of vinyl-terminated RTV-615 prepolymer can make hydrogenated nitrile rubber have an appropriate crosslinking structure. DETAILED DESCRIPTION

[0040] The present application is further described in detail below in conjunction with Examples 1-7 and Comparative Example 1.

[0041] raw material

[0042] Nitrile latex (CAS: 9003-18-3); Deionized water (CAS: 7732-18-5); Anhydrous copper sulfate (CAS: 7758-98-7); Sodium lauryl sulfate (CAS: 151-21-3); Hydrazine hydrate (CAS: 10217-52-4); Hydrogen peroxide (CAS: 7722-84-1); Calcium chloride (CAS: 22691-02-7); Prepolymer RTV615-A (Shenzhen Huazhisheng New Material Technology Co., Ltd.); Crosslinker RTV615-B (Shenzhen Huazhisheng New Material Technology Co., Ltd.); Hexane (CAS: 110-54-3).

[0043] Example

[0044] Example 1

[0045] A process for preparing a blowout preventer rubber core with excellent corrosion resistance includes the following raw materials: 150g of nitrile latex, 300g of deionized water, 0.008g of anhydrous copper sulfate, 0.15g of sodium lauryl sulfate, 229g of hydrazine hydrate, 98g of hydrogen peroxide, 5.4g of calcium chloride solution, and 138g of polydimethylsiloxane solution.

[0046] Specifically, the method for preparing a blowout preventer rubber core with excellent corrosion resistance includes the following steps:

[0047] S1: Take a 1000ml three-necked flask, weigh 150g of latex with a solid content of 17% and an acrylonitrile content of 33%, add it to the three-necked flask, turn on the stirring motor and set the speed to 260r / min for stirring;

[0048] S2: Weigh 300 g of deionized water into a three-necked flask and add 7 ml of defoamer during stirring;

[0049] S3: Then, 0.008 g of anhydrous copper sulfate, 0.15 g of sodium lauryl sulfate, and 229 g of hydrazine hydrate were added in sequence;

[0050] S4: Using a constant pressure funnel, 98 g of hydrogen peroxide was added dropwise. The rate of addition of hydrogen peroxide was adjusted so that the hydrogen peroxide could be added within 6 h. After the hydrogen peroxide was completely added, the reaction was continued for 1 h to obtain hydrogenated nitrile latex.

[0051] S5: Pour the hydrogenated nitrile latex into a large beaker and place it in a water bath at 5°C. Add 5.4 g of a 20% calcium chloride solution to obtain flocculated hydrogenated nitrile latex.

[0052] S6: Soaking the flocculated hydrogenated nitrile latex in deionized water for 24 hours, and then taking it out and drying it to obtain hydrogenated nitrile rubber;

[0053] S7: 10g RTV615-A and 1g RTV615-B were thoroughly mixed, added to 126.5g of 8% polydimethylsiloxane solution prepared in n-hexane, and reacted for 24h;

[0054] S8: The hydrogenated nitrile rubber was completely immersed in 138 g of polydimethylsiloxane solution. After soaking for 1.5 hours, the mixture was taken out and hung in a ventilated place to dry. The mixture was then placed in an oven at 60° C. and cured for 24 hours to obtain a modified hydrogenated nitrile rubber.

[0055] Example 2-3

[0056] The difference from Example 1 is that the addition amounts of the components of the blowout preventer rubber core with excellent corrosion resistance are different, as shown in Table 1.

[0057] Table 1 Addition amount of each component of the blowout preventer rubber core with excellent corrosion resistance in Examples 1-3 (g)

[0058]

[0059] Example 4

[0060] The difference from Example 1 is that hydrogenated nitrile rubber is replaced by nitrile rubber;

[0061] Example 5

[0062] The difference from Example 1 is that the mass ratio of the prepolymer RTV615-A to the cross-linking agent RTV615-B is 8:2.

[0063] Examples 6-7

[0064] The difference from Example 1 is that the addition amount of each component of the polydimethylsiloxane solution is different, as shown in Table 2.

[0065] Table 2 Addition amount of each component of polydimethylsiloxane solution in Examples 1-3 (g)

[0066]

[0067] Comparative Example

[0068] Comparative Example 1

[0069] The difference from Example 1 is that no polydimethylsiloxane solution is added.

[0070] Performance testing

[0071] Detection method

[0072] 1. Anti-corrosion performance test

[0073] Three samples were taken from each of Examples 1-7 and Comparative Example 1, and the anti-corrosion performance was tested according to NACE TM0187-2011 “Standard Test Method for Evaluating Elastomeric Materials in Sour Gas Environments”.

[0074] The test data is shown in Table 3.

[0075] Table 3 Anticorrosion performance test table of Examples 1-7 and Comparative Example 1

[0076]

[0077] Combining Example 1 and Comparative Example 1 and Table 3, it can be seen that, relative to Example 1, the hardness, tensile strength and elongation at break of the sample of Comparative Example 1 before hydrogen sulfide corrosion are greatly reduced, and the hardness, tensile strength and elongation at break of the sample of Example 1 after hydrogen sulfide vapor corrosion are slightly reduced compared to the hardness, tensile strength and elongation at break before hydrogen sulfide vapor corrosion, compared to the slight reduction in Example 1. The hardness, tensile strength and elongation at break of the sample of Comparative Example 1 after hydrogen sulfide vapor corrosion are significantly reduced compared to the hardness, tensile strength and elongation at break before hydrogen sulfide vapor corrosion. At the same time, the mass change rate of Comparative Example 1 is significantly increased compared to the mass change rate of Example 1, which shows that the addition of polydimethylsiloxane solution can effectively improve the corrosion resistance of hydrogenated nitrile rubber.

[0078] The reason is that the acrylonitrile group in hydrogenated nitrile rubber is a polar functional group containing a carbon-nitrogen triple bond and has certain chemical reactivity. During oil exploration, the acrylonitrile group will react with hydrogen sulfide to form thioamide, thereby accelerating the aging and degradation of the hydrogenated nitrile rubber and causing the corrosion resistance of the hydrogenated nitrile rubber to decline. After adding the polydimethylsiloxane solution, the acrylonitrile group in the hydrogenated nitrile rubber can form a cross-linked structure through reaction in the polydimethylsiloxane. This cross-linking occurs not only between the acrylonitrile groups, but also between the acrylonitrile groups and the silicon oxygen chains of the polydimethylsiloxane, thereby forming a dense network structure on the surface of the hydrogenated nitrile rubber, making it difficult for hydrogen sulfide to enter the hydrogenated nitrile rubber and react with the acrylonitrile groups, thereby improving the corrosion resistance of the hydrogenated nitrile rubber.

[0079] In conjunction with Examples 1-3 and in conjunction with Table 3, it can be seen that, relative to Example 1, the hardness, tensile strength and elongation at break of the samples of Examples 2 and 3 before hydrogen sulfide corrosion all decrease, and the hardness, tensile strength and elongation at break obtained by the sample of Example 1 after hydrogen sulfide vapor corrosion are slightly reduced compared to the hardness, tensile strength and elongation at break before hydrogen sulfide vapor corrosion, compared to the slightly reduced amount of Example 1, the hardness, tensile strength and elongation at break obtained by the samples of Examples 2 and 3 after hydrogen sulfide vapor corrosion are significantly reduced compared to the hardness, tensile strength and elongation at break before hydrogen sulfide vapor corrosion, and the mass change rate of Example 2 and Example 3 is increased compared to the mass change rate of Example 1, which illustrates that the addition amount of each component also affects the corrosion resistance of hydrogenated nitrile rubber, and the addition amount of each component in Example 1 can obtain a hydrogenated nitrile rubber with excellent corrosion resistance.

[0080] Combining Example 1 and Example 4 and Table 3, it can be seen that, relative to Example 1, the hardness, tensile strength and elongation at break of the sample of Example 4 before hydrogen sulfide corrosion are all reduced, and the hardness, tensile strength and elongation at break of the sample of Example 1 after hydrogen sulfide vapor corrosion are slightly reduced compared to the hardness, tensile strength and elongation at break before hydrogen sulfide vapor corrosion, compared to the slight reduction in Example 1. The hardness, tensile strength and elongation at break of the sample of Example 4 after hydrogen sulfide vapor corrosion are significantly reduced compared to the hardness, tensile strength and elongation at break before hydrogen sulfide vapor corrosion, and the mass change rate of Example 4 is increased compared to the mass change rate of Example 1. This indicates that the corrosion resistance of the rubber core obtained by reacting hydrogenated nitrile rubber with polydimethylsiloxane solution is better than the corrosion resistance of the rubber core obtained by reacting nitrile rubber with polydimethylsiloxane solution.

[0081] It can be seen from Example 1 and Example 5 and Table 3 that, relative to Example 1, the hardness, tensile strength and elongation at break of the sample of Example 5 before hydrogen sulfide corrosion are reduced, and the hardness, tensile strength and elongation at break obtained from the sample of Example 1 after hydrogen sulfide vapor corrosion are slightly reduced compared to the hardness, tensile strength and elongation at break before hydrogen sulfide vapor corrosion, compared to the slight reduction in Example 1. The hardness, tensile strength and elongation at break obtained from the sample of Example 5 after hydrogen sulfide vapor corrosion are significantly reduced compared to the hardness, tensile strength and elongation at break before hydrogen sulfide vapor corrosion, and the mass change rate of Example 5 is increased compared to the mass change rate of Example 1, which indicates that the mass ratio of prepolymer RTV615-A to the cross-linking agent RTV615-B also affects the corrosion resistance of hydrogenated nitrile rubber.

[0082] In combination with Example 1 and Example 6-7 and in combination with Table 3, it can be seen that, relative to Example 1, the hardness, tensile strength and elongation at break of the samples of Example 6 and Example 7 before hydrogen sulfide corrosion are greatly reduced, and the hardness, tensile strength and elongation at break obtained by the sample of Example 1 after hydrogen sulfide vapor corrosion are slightly reduced compared to the hardness, tensile strength and elongation at break before hydrogen sulfide vapor corrosion, compared to the slightly reduced embodiment 1, the hardness, tensile strength and elongation at break obtained by the samples of Example 6 and Example 7 after hydrogen sulfide vapor corrosion are significantly reduced compared to the hardness, tensile strength and elongation at break before hydrogen sulfide vapor corrosion, and the mass change rate of Example 6 and Example 7 is increased. This shows that the addition amount of each component of the polydimethylsiloxane solution also affects the corrosion resistance of the hydrogenated nitrile rubber, and the addition amount of each component of the polydimethylsiloxane solution in Example 1 can obtain a hydrogenated nitrile rubber with excellent corrosion resistance.

[0083] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A process for preparing a blowout preventer rubber core with excellent corrosion resistance, characterized in that: The following steps are involved: S1: Weigh nitrile latex and stir; S2: Add deionized water and stir, then add defoamer; S3: adding anhydrous copper sulfate, sodium lauryl sulfate, and hydrazine hydrate in sequence; S4: adding hydrogen peroxide dropwise, and after the hydrogen peroxide is completely added, the reaction is continued to obtain hydrogenated nitrile latex; S5: placing the hydrogenated nitrile butadiene rubber latex in a water bath environment and adding a calcium chloride solution to obtain flocculated hydrogenated nitrile butadiene rubber; S6: soaking the flocculated hydrogenated nitrile rubber in deionized water, taking it out and drying it to obtain hydrogenated nitrile rubber; S7: completely immersing the hydrogenated nitrile rubber in the polydimethylsiloxane solution, taking it out after immersion and hanging it in a ventilated place to dry, and then placing it in an oven for curing to obtain a modified hydrogenated nitrile rubber; in: S1: Weigh 148g-152g of nitrile latex with a solid content of 15%-19% and an acrylonitrile content of 32%-34% and stir; S2: Add 297g-303g of deionized water and stir, then add 5-10ml of defoamer; S3: Add 0.005g-0.011g of anhydrous copper sulfate, 0.13g-0.17g of sodium lauryl sulfate, and 225g-233g of hydrazine hydrate in sequence; S4: Add 95g-101g of hydrogen peroxide dropwise. After the hydrogen peroxide is completely added, continue the reaction for 0.5h-1.5h to obtain hydrogenated nitrile latex; S5: placing the hydrogenated nitrile butadiene rubber latex in a water bath at 3-7°C, adding 5 g-5.8 g of a 19%-21% calcium chloride solution to obtain flocculated hydrogenated nitrile butadiene rubber; S6: Soaking the flocculated hydrogenated nitrile rubber in deionized water for 22-26 hours, taking it out and drying it to obtain hydrogenated nitrile rubber; S7: completely immerse the hydrogenated nitrile rubber in 136g-140g of polydimethylsiloxane solution for 1h-2h, then take it out and hang it in a ventilated place to dry, and then place it in an oven at 55-65°C for curing for 23-25h to obtain a modified hydrogenated nitrile rubber; The polydimethylsiloxane solution comprises the following raw materials: 9.8g-12.2g vinyl terminated RTV-615 type prepolymer and 124.5-128.5g n-hexane; The vinyl terminated RTV-615 type prepolymer comprises a prepolymer RTV615-A and a crosslinking agent RTV615-B; The vinyl terminated RTV-615 prepolymer comprises 9g-11g of prepolymer RTV615-A and 0.8g-1.2g of crosslinker RTV615-B; The mass ratio of the prepolymer RTV615-A to the crosslinking agent RTV615-B is 10:

1.

2. The process for preparing a blowout preventer rubber core with excellent corrosion resistance according to claim 1, characterized in that: The vinyl terminated RTV-615 prepolymer is MOMENTIVE RTV-615 prepolymer.

3. The process for preparing a blowout preventer rubber core with excellent corrosion resistance according to claim 1, characterized in that: The polydimethylsiloxane solution is prepared by fully mixing 9g-11g of RTV615-A and 0.8g-1.2g of RTV615-B, adding 124.5-128.5g of n-hexane to a polydimethylsiloxane solution with a mass fraction of 7-9%, and reacting for 22-26h.

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