Cold-resistant and compression-resistant hydrogenated nitrile rubber for oil field and preparation method thereof

Abstract

The invention discloses cold-resistant and compression-resistant hydrogenated butadiene-acrylonitrile rubber for an oil field and a preparation method of the cold-resistant and compression-resistant hydrogenated butadiene-acrylonitrile rubber. The preparation method comprises the following steps: (1) preparing a functionalized macromolecular long branch chain grafting agent; and (2) preparing the cold-resistant and compression-resistant hydrogenated butadiene-acrylonitrile rubber for the oil field. The functionalized macromolecular long branch chain grafting agent has the following structure: # imgabs0 #, wherein IR is an isoprene homopolymer segment with wide vinyl distribution; the SBR is a random block copolymer segment of styrene and 1, 3-butadiene; b is terminated 1, 3-butadiene, n is the number of repetitive units, and n is a positive integer greater than or equal to 1; the number-average molecular weight (Mn) of the functionalized macromolecular long branch chain grafting agent is 5000 to 7000, and the molecular weight distribution (Mw / Mn) of the functionalized macromolecular long branch chain grafting agent is 6.14 to 7.86. The preparation method of the cold-resistant and compression-resistant hydrogenated butadiene-acrylonitrile rubber for the oil field has the characteristics of environment friendliness, efficient modification effect, low dosage of a modifier, commercially available and easily available raw materials, suitability for industrial production and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of rubber, and in particular relates to a cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields modified by a functionalized macromolecular long-branch grafting agent and a preparation method thereof. Background Art

[0002] Hydrogenated nitrile rubber (HNBR for short) is prepared by selective hydrogenation of carbon-carbon double bonds in nitrile rubber. Therefore, HNBR not only retains the oil resistance, corrosion resistance and elasticity of NBR, but also exhibits excellent aging resistance and high temperature resistance. The mechanical properties such as tensile strength, elongation at break, wear resistance and hardness are improved. It is widely used in oil exploration equipment such as pump pistons, rotary hoses, valve seals, drill pipe shields, etc.

[0003] Although hydrogenation of carbon-carbon double bonds gives HNBR very excellent performance, it also brings a serious defect to HNBR materials. The main chain of hydrogenated nitrile rubber (NBR) is a highly ordered polyethylene structure, which is very easy to form a crystalline structure and causes an increase in Tg. Therefore, the low-temperature resistance of HNBR products is poor. Since most of my country's oil drilling business is concentrated in the western and northeastern regions, the lowest temperature in these regions can reach about -50℃. Oil drilling equipment faces an application environment under low temperature conditions, which puts forward extremely high requirements on the low-temperature resistance of rubber sealing materials.

[0004] In the prior art, there are many patent documents reporting on the preparation method of low temperature resistant hydrogenated nitrile rubber. For example:

[0005] CN 106349410 B discloses a special hydrogenated nitrile rubber with compression cold resistance and a preparation method thereof, wherein the rubber main chain contains epoxy groups, and part of the epoxy groups are also connected to ester side groups; the ester side groups are generated by the ring-opening reaction of C6-C24 acid anhydride and the epoxy groups. The preparation method comprises introducing epoxy groups into the main chain of the rubber molecule, and then reacting part of the epoxy groups with acid anhydride under the action of a catalyst to introduce ester groups, thereby obtaining a special hydrogenated nitrile rubber containing epoxy groups and ester groups. CN 105294939B discloses a low-temperature grade hydrogenated nitrile rubber raw rubber, which is a copolymer of butadiene, acrylonitrile and dibutyl fumarate, and the number average molecular weight of the copolymer is 1.05 to 3.25×10 5 , weight average molecular weight is 3.02~9.32×10 5, the polydispersity coefficient is 2.0-2.7; the low-temperature grade hydrogenated nitrile rubber raw rubber has a hydrogenation degree of more than 90% and a glass transition temperature of -38°C to -42°C. CN 112592461 B discloses a modified hydrogenated nitrile rubber material with the characteristics of low temperature resistance and high damping, and its preparation method and application. The modified hydrogenated nitrile rubber material is prepared using HNBR / PNB block copolymer as raw material; the HNBR / PNB block copolymer is obtained by modifying NBR or HNBR through olefin metathesis reaction using norbornene monomer as a modifier. CN 115594898A discloses a low-temperature resistant hydrogenated nitrile rubber compound and a banburying preparation method thereof, which mainly comprises blending and banburying hydrogenated nitrile raw rubber, a plasticizer and a hardness regulator, and finally obtaining a low-temperature resistant hydrogenated nitrile rubber compound having a Shore A hardness of 67±5, a tensile strength ≥14MPa, an elongation at break ≥180%, a compression permanent deformation ≤35%, and a 45°C compression cold resistance coefficient ≥0.16. CN 105754164A discloses a low-temperature resistant rubber material, although the low-temperature resistance of the material is improved, the addition of the plasticizer dioctyl phthalate (DOP) reduces the mechanical properties and oil resistance of the material, and DOP is not environmentally friendly and is easy to precipitate. Zhang Dongheng et al. disclosed that ethylene propylene rubber (EPDM) and HNBR were blended to improve the low temperature performance of HNBR. When the EPDM addition amount was 15%, the Tg decreased by 3°C. However, when the EPDM addition amount was further increased, the Tg of the blended rubber did not decrease any more (Synthetic Rubber Industry, 2002, 25(1): ).

[0006] In the above-mentioned prior art, although the low temperature resistance of hydrogenated nitrile rubber can be improved to a certain extent by adding small molecule modifiers, copolymerization and blending, these methods still have certain limitations, and the preparation methods thereof have the problems of complex process, difficulty in actual operation, large addition amount, high cost, and unclear modification effect. Summary of the invention

[0007] In order to solve the problems existing in the prior art, the present invention provides a method for preparing a cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields, which has a compression permanent deformation resistance of ≤26% and a glass transition temperature Tg<-61°C and can meet the requirements of use within the range of -61°C to -63°C. The invention first adopts an anionic polymerization method to prepare a functionalized macromolecular long-branched grafting agent with free radical reaction activity containing a wide vinyl distribution and random segments by distributed synthesis from the reaction monomers of isoprene, styrene, 1,3-butadiene and dihydromyrcenol; secondly, the functionalized macromolecular long-branched grafting agent is grafted onto the main chain of hydrogenated nitrile rubber to prepare a cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields. The method not only solves the problem of easy crystallization of hydrogenated nitrile rubber, but also improves the viscoelasticity of hydrogenated nitrile rubber, so that the hydrogenated nitrile rubber shows very excellent low temperature resistance and deformation resistance, and achieves a balance between the low temperature resistance and deformation resistance of hydrogenated nitrile rubber. It is very suitable for oil well operations under low temperature conditions with an operating temperature of -61°C.

[0008] Unless otherwise specified, the "parts" described in the present invention refer to parts by mass, the "%" described refers to mass percentage, and the "ratio" described refers to mass ratio.

[0009] In order to achieve the above object, the present invention provides a method for preparing cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields, the preparation method comprising the following steps:

[0010] (1) Preparation of functionalized macromolecular long-branched grafting agent:

[0011] In a polymerization kettle, argon gas is introduced for replacement, and a solvent, isoprene, a first structural regulator, and an initiator 1 are sequentially added to the polymerization kettle. The reaction is a temperature-variable polymerization. Within 50 to 60 minutes, the temperature is gradually increased from 45° C. to 65° C. to form an IR segment with a wide vinyl distribution; then the temperature is increased to 70 to 80° C., 1,3-butadiene, styrene, and a second structural regulator are sequentially added to the polymerization kettle, and the reaction is performed for 70 to 80 minutes to form an SBR random segment; then a functional monomer dihydromyrcenol and a third structural regulator are added to the polymerization kettle, and the reaction is performed for 40 to 50 minutes; finally, 1,3-butadiene is added to the polymerization kettle for end-capping, and the reaction is performed for 20 to 30 minutes until no free monomer exists. The glue solution is subjected to wet coagulation and drying to obtain a functional macromolecular long-branch grafting agent;

[0012] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields:

[0013] a Preparation of hydrogenated nitrile rubber (HNBR): dissolving nitrile rubber in chlorobenzene solution to prepare a rubber solution, then adding the rubber solution into a reactor and introducing an inert gas to remove the air in the reactor, then removing the inert gas in the reactor with hydrogen, adding a xylene solution of Grubbs I catalyst under nitrogen protection, pressurizing, heating, reacting, cooling the system, condensing, and drying to obtain HNBR rubber;

[0014] b. Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields: HNBR rubber is dissolved in chlorobenzene solution to prepare a glue solution, and then the glue solution is added to a reactor, and an inert gas is introduced for replacement, and then a functionalized macromolecular long-branched grafting agent is added to the reactor, stirred and mixed, heated, and a mixed solution of initiator 2 and chlorobenzene is added. After the reaction, flocculation, washing, and drying are performed to obtain cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields;

[0015] The functionalized macromolecular long-branched grafting agent has the following structure:

[0016]

[0017] Among them, IR is an isoprene homopolymer segment with a wide vinyl distribution; SBR is a random block copolymer segment of styrene and 1,3-butadiene; B is a terminal 1,3-butadiene, n is the number of repeating units, and n is a positive integer of ≥1; the number average molecular weight (Mn) of the functionalized macromolecular long-branched grafting agent is 5000-7000, and the molecular weight distribution (Mw / Mn) is 6.14-7.86.

[0018] The initiator 1 of the present invention is a hydrocarbon monolithium compound, namely RLi, wherein R is a saturated aliphatic hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon group or a composite group of the above groups containing 1 to 20 carbon atoms. The hydrocarbon monolithium compound is selected from one of n-butyl lithium, sec-butyl lithium, methylbutyl lithium, phenylbutyl lithium, naphthalene lithium, cyclohexyl lithium and dodecyl lithium, preferably n-butyl lithium. The amount of organic lithium added is determined by the molecular weight of the designed polymer.

[0019] The initiator 2 described in the present invention is an organic peroxide, selected from one of diacetyl peroxide, diisobutyryl peroxide, cumene hydroperoxide, dicumyl peroxide (DCP) and dibenzoyl peroxide, preferably dicumyl peroxide (DCP), and the amount of the added peroxide is 0.05-0.3 parts, preferably 0.1-0.2 parts, based on 100 parts by mass of the HNBR rubber.

[0020] The nitrile rubber of the present invention is copolymerized by emulsion polymerization of 1,3-butadiene and acrylonitrile, wherein the acrylonitrile content of the nitrile rubber is 20wt% to 42wt%, preferably 22wt% to 35wt%.

[0021] The structure regulator of the present invention is a polar organic compound that produces a solvation effect in the polymerization system, and can adjust the reactivity ratio of styrene and 1,3-butadiene to make the two copolymerize randomly. This type of polar organic compound is selected from one of diethylene glycol dimethyl ether (2G), tetrahydrofuran (THF), ethyl ether, ethyl methyl ether, anisole, diphenyl ether, ethylene glycol dimethyl ether (DME), and triethylamine, preferably tetrahydrofuran (THF).

[0022] The solvent of the present invention can be selected from one of cyclohexane, carbon disulfide (CS2), nitrobenzene, petroleum ether, tetrachloroethane, toluene and xylene, preferably cyclohexane.

[0023] In step (1) of the present invention, in the step (1), during the formation of the SBR random segments, the mass ratio of the solvent, isoprene, structure regulator, 1,3-butadiene, styrene, and the second structure regulator is 200-300:100:0.2-0.5:30-40:20-30:0.5-1.0;

[0024] In the end-capping process, the mass ratio of the dihydromyrcenol, the third structural regulator, and 1,3-butadiene is 10-20:0.1-0.5:2-4.

[0025] In step (2) a of the present invention, the mass ratio of the nitrile rubber to the Grubbs I catalyst is 100:0.02-0.1.

[0026] In step (2) a of the present invention, the mass fraction of nitrile rubber in the rubber solution is 3% to 6%.

[0027] In step (2) a of the present invention, in the xylene solution of the Grubbs I catalyst, the mass concentration of the Grubbs I catalyst is 5% to 10%.

[0028] In step (2) a of the present invention, the pressurization is performed to a pressure of 11 to 14 MPa; the heating is performed to a temperature of 100 to 120° C.; and the reaction time is 9 to 11 hr.

[0029] In step (2) a of the present invention, the degree of hydrogenation HD of the HNBR rubber is less than 90%.

[0030] In step (2) b of the present invention, the mass ratio of the HNBR rubber, the functionalized macromolecular long-chain branching grafting agent, and chlorobenzene is 100:3-5:100-200.

[0031] In step (2) b of the present invention, the mass fraction of HNBR rubber in the rubber solution is 6% to 9%.

[0032] In step (2) b of the present invention, the reaction temperature is 70-80° C. and the reaction time is 10.0-12.0 hr.

[0033] In step (2) b of the present invention, the grafting rate of the cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields is 2.3% to 3.4%.

[0034] The polymerization reaction of the present invention is carried out in an oxygen-free, water-free and inert gas environment. The inert gas is nitrogen or a gas of a Group 0 element in the periodic table except radon, preferably nitrogen.

[0035] The high-pressure reactor of the present invention can be a loop reactor or a tank reactor, preferably a tank reactor.

[0036] The pressurization in step (2) a of the present invention is achieved by adding hydrogen. The amount of hydrogen added is well known to those skilled in the art and is within the conventional addition range in the prior art, and is not particularly limited in the present invention.

[0037] The present invention also provides a cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields obtained by the preparation method.

[0038] Compared with the prior art, the present invention has at least the following advantages and beneficial effects:

[0039] (1) The functional macromolecular long-branched grafting agent prepared by the present invention utilizes an anionic polymerization method to prepare a macromolecular copolymer having free radical reaction activity, containing a broad vinyl distribution isoprene homopolymer segment (IR), a styrene and 1,3-butadiene random block copolymer segment (SBR) and a long carbon chain hydroxyl group through distributed synthesis and variable temperature polymerization; the macromolecular copolymer can be grafted onto hydrogenated nitrile rubber, and a branched structure containing a broad distribution of unsaturated double bonds, a randomly distributed benzene ring and a copolymer segment of 1,3-butadiene and a long carbon chain hydroxyl group is formed on the main chain structure of the hydrogenated nitrile rubber. This structure has a very significant effect in destroying the crystallinity of HNBR and improving viscoelasticity, and achieves a good "synergistic effect" in achieving a balance between low temperature resistance and deformation resistance, and can prepare a cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields with a compression set of ≤26% and a glass transition temperature Tg<-61°C.

[0040] (2) The cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields prepared by the present invention fully utilizes the "aggregation effect", "group effect" and "structural effect" of hydroxyl groups, benzene rings and unsaturated double bonds under the condition of ensuring a certain degree of hydrogenation. It can greatly reduce the glass transition temperature (Tg) of HNBR with a low addition amount, and can also significantly improve the compression set resistance of HNBR. It is suitable for oil well operations under low temperature conditions of -61°C.

[0041] (3) The preparation method of the cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields of the present invention is green and environmentally friendly, has a high modification effect, uses a low amount of modifier, and has readily available raw materials on the market, and is suitable for industrial production. DETAILED DESCRIPTION

[0042] The following examples and comparative examples are listed to illustrate the effects of the present invention, but the protection scope of the present invention is not limited to these examples and comparative examples. The raw materials used in the examples are all industrial grade and used after purification without other special requirements. The "parts" described in the examples and comparative examples are all parts by mass.

[0043] (1) Source of raw materials:

[0044]

[0045] (2) Analytical testing methods:

[0046] Determination of grafting rate: Take about 4g of sample from the three-necked bottle with a pipette and put it into a weighing bottle. After weighing, add 2-3 drops of hydroquinone solution and dry to constant weight. Then put the sample in a Soxhlet fat extractor and extract it with toluene in a 90℃ water bath for 24 hours, and then dry it to constant weight. Calculate the monomer grafting rate according to the following formula:

[0047]

[0048] Where: m0 is the total mass of the mortar (g); m is the mass of the sample weighed after the reaction (g); m —Total mass of monomers in the reactants (g); m HNBR —The mass of hydrogenated nitrile rubber in the sample (g); m1—The mass of the sample after extraction (g).

[0049] Molecular weight determination: The determination was performed using a 2414 gel permeation chromatograph (GPC) produced by Waters, USA. The polystyrene standard was used as the calibration curve, the mobile phase was tetrahydrofuran, the column temperature was 40°C, the sample concentration was 1 mg / ml, the injection volume was 50 μL, the elution time was 40 min, and the flow rate was 1 ml·min -1 .

[0050] Determination of HNBR hydrogenation degree: Using nuclear magnetic resonance hydrogen spectrum ( 1The degree of hydrogenation of hydrogenated nitrile rubber is calculated by HNMR (HNMR), and the main method is as follows: 1. The product is completely dissolved in deuterated chloroform to prepare a nuclear magnetic resonance hydrogen spectrum sample; 2. After measuring the nuclear magnetic resonance hydrogen spectrum, its spectrum is analyzed: The degree of hydrogenation of hydrogenated nitrile rubber is measured by nuclear magnetic resonance hydrogen spectrum, and is calculated according to the following method: the proton characteristic peak of 1,4-C=C-: 5.4ppm, the proton characteristic peak of 1,2-C=C-: 5.0ppm, the proton characteristic peak of saturated hydrocarbons: 1.25ppm, the proton characteristic peak of cyano-linked: 2.5ppm, and the calculation formula of the degree of hydrogenation is as follows:

[0051] Degree of hydrogenation HD (%) = 1-unsaturation (U)

[0052] Determination of glass transition temperature Tg: DSC is used to measure the glass transition temperature of the product. The instrument model is DSC1, the company is Swiss Mettler, the temperature rise range is -80 to 80°C, and the temperature rise rate is 10°C / min.

[0053] Compression set: Execute the method in standard GB / T 7759.1-2015.

[0054] Example 1

[0055] (1) Preparation of functionalized macromolecular long-branched grafting agent:

[0056] In a 10L stainless steel polymerizer with a jacket, argon was passed through the system to replace it three times, and 1000g cyclohexane, 500g isoprene, and 1.0g THF were added to the polymerizer in sequence. The temperature was raised to 45°C, and 165mmol n-butyl lithium was added to start the reaction. The reaction temperature gradually increased from 45°C to 65°C within 50min to form an IR segment with a wide vinyl distribution; then the temperature was raised to 70°C, and 150g 1,3-butadiene, 100g styrene, and 2.5g THF were added to the polymerizer in sequence, and the reaction was carried out for 70min to form an SBR random segment; then 50g dihydromyrcenol and 0.5g THF were added to the polymerizer and the reaction was carried out for 40min; finally, 10g The 1,3-butadiene was capped and the reaction was carried out for 20 minutes until no free monomer was present. The gel was coagulated and dried by a wet method to obtain a functional macromolecular long-branched grafting agent (Mn was 5000, Mw / Mn was 6.14).

[0057] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields:

[0058] a Preparation of hydrogenated nitrile rubber (HNBR): First, 100g of nitrile rubber 2907 was dissolved in chlorobenzene solution to prepare a 3% rubber solution by mass, and then the rubber solution was added to a 10L high-pressure reactor and nitrogen was introduced to remove the air in the reactor. Then, the nitrogen in the reactor was removed with hydrogen for 30 minutes, and then 0.02g of GrubbsⅠ catalyst xylene solution (mass concentration of 5%) was added under nitrogen protection. The hydrogen pressure in the pressurized reactor was 11MPa, the temperature was raised to 100℃, and after reacting for 9.0hr, the system was cooled, condensed, and vacuum dried to obtain HNBR rubber (hydrogenation degree HD=84.1%).

[0059] b Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields: First, 200g HNBR rubber was dissolved in chlorobenzene solution to prepare a 6% glue solution by mass, and then the glue solution was added to a 10L stainless steel reactor with a jacket, and nitrogen was introduced for replacement 3 times, and then 6.0g of functionalized macromolecular long-branched grafting agent was added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reached 70°C, a mixture of 0.10g DCP and 200g chlorobenzene was added. After reacting for 10.0 hours, it was flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields (grafting rate 2.3%). Sampling analysis: Standard samples were made, and the tested properties are shown in Table 1.

[0060] Example 2

[0061] (1) Preparation of functionalized macromolecular long-branched grafting agent:

[0062] In a 10L stainless steel polymerizer with a jacket, argon was passed through the system to replace it three times, and 1100g cyclohexane, 500g isoprene, and 1.3g THF were added to the polymerizer in sequence. The temperature was raised to 45°C, and 156mmol n-butyl lithium was added to start the reaction. The reaction temperature gradually increased from 45°C to 65°C within 52min to form an IR segment with a wide vinyl distribution; then the temperature was raised to 72°C, and 160g 1,3-butadiene, 110g styrene, and 3.0g THF were added to the polymerizer in sequence, and the reaction was carried out for 72min to form an SBR random segment; then 60g dihydromyrcenol and 1.0g THF were added to the polymerizer and the reaction was carried out for 42min; finally, 12g The 1,3-butadiene was capped and the reaction was continued for 22 min until no free monomer was present. The gel was coagulated and dried by wet method to obtain a functional macromolecular long-branch grafting agent (Mn was 5600, Mw / Mn was 6.53).

[0063] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields:

[0064] a Preparation of hydrogenated nitrile rubber (HNBR): First, 100g of nitrile rubber 2907 was dissolved in chlorobenzene solution to prepare a 3% rubber solution by mass, and then the rubber solution was added to a 10L high-pressure reactor and nitrogen was introduced to remove the air in the reactor. Then, the nitrogen in the reactor was removed with hydrogen for 32 minutes, and then 0.03g of GrubbsⅠ catalyst xylene solution (mass concentration of 6%) was added under nitrogen protection. The hydrogen pressure in the pressurized reactor was 12MPa, the temperature was raised to 105℃, and after reacting for 9.5hr, the system was cooled, condensed, and vacuum dried to obtain HNBR rubber (hydrogenation degree HD=85.7%).

[0065] b Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields: First, 200g HNBR rubber was dissolved in chlorobenzene solution to prepare a 6.5% glue solution by mass, and then the glue solution was added to a 10L stainless steel reactor with a jacket, and nitrogen was introduced for replacement 3 times, and then 7.0g of functionalized macromolecular long-branched grafting agent was added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reached 72°C, a mixture of 0.12g DCP and 260g chlorobenzene was added. After reacting for 10.5 hours, it was flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields (grafting rate 2.5%). Sampling analysis: Standard samples were made, and the tested properties are shown in Table 1.

[0066] Example 3

[0067] (1) Preparation of functionalized macromolecular long-branched grafting agent:

[0068] In a 10L stainless steel polymerizer with a jacket, argon was passed through the system to replace it 4 times, and 1200g cyclohexane, 500g isoprene, and 1.8g THF were added to the polymerizer in sequence. The temperature was raised to 45°C, and 142mmol n-butyl lithium was added to start the reaction. The reaction temperature gradually increased from 45°C to 65°C within 54min to form an IR segment with a wide vinyl distribution; then the temperature was raised to 74°C, and 170g 1,3-butadiene, 120g styrene, and 3.5g THF were added to the polymerizer in sequence, and the reaction was carried out for 74min to form an SBR random segment; then 70g dihydromyrcenol and 1.5g THF were added to the polymerizer and the reaction was carried out for 44min; finally, 14g The 1,3-butadiene was capped and the reaction was carried out for 24 minutes until no free monomer was present. The gel was coagulated and dried by wet method to obtain a functional macromolecular long-branched grafting agent (Mn was 5900, Mw / Mn was 6.87).

[0069] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields:

[0070] a Preparation of hydrogenated nitrile rubber (HNBR): First, 100g of nitrile rubber 2907 was dissolved in chlorobenzene solution to prepare a 4% rubber solution by mass, and then the rubber solution was added to a 10L high-pressure reactor and nitrogen was introduced to remove the air in the reactor. Then, the nitrogen in the reactor was removed with hydrogen for 34 minutes, and then 0.05g of GrubbsⅠ catalyst xylene solution (mass concentration was 7%) was added under nitrogen protection. The hydrogen pressure in the pressurized reactor was 12MPa, and the temperature was raised to 110°C. After reacting for 10 hours, the system was cooled, condensed, and vacuum dried to obtain HNBR rubber (hydrogenation degree HD=86.2%).

[0071] b Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields: First, 200g HNBR rubber was dissolved in chlorobenzene solution to prepare a 7.0% glue solution by mass, and then the glue solution was added to a 10L stainless steel reactor with a jacket, and nitrogen was introduced for replacement 4 times, and then 8.0g of functionalized macromolecular long-branched grafting agent was added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reached 74°C, a mixture of 0.14g DCP and 290g chlorobenzene was added. After reacting for 11 hours, it was flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields (grafting rate 2.7%). Sampling analysis: Standard samples were made, and the tested properties are shown in Table 1.

[0072] Example 4

[0073] (1) Preparation of functionalized macromolecular long-branched grafting agent:

[0074] In a 10L stainless steel polymerizer with a jacket, argon was passed through the system to replace it 4 times, and 1300g cyclohexane, 500g isoprene, and 2.0g THF were added to the polymerizer in sequence. The temperature was raised to 45°C, and 134mmol n-butyl lithium was added to start the reaction. The reaction temperature gradually increased from 45°C to 65°C within 56min to form an IR segment with a wide vinyl distribution; then the temperature was raised to 76°C, and 180g 1,3-butadiene, 130g styrene, and 4.0g THF were added to the polymerizer in sequence, and the reaction was carried out for 76min to form an SBR random segment; then 80g dihydromyrcenol and 2.0g THF were added to the polymerizer and the reaction was carried out for 46min; finally, 16g The 1,3-butadiene was capped and the reaction was continued for 26 min until no free monomer was present. The gel was coagulated and dried by wet method to obtain a functional macromolecular long-branch grafting agent (Mn was 6200, Mw / Mn was 7.12).

[0075] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields:

[0076] a Preparation of hydrogenated nitrile rubber (HNBR): First, 100g of nitrile rubber 2907 was dissolved in chlorobenzene solution to prepare a 4.5% rubber solution by mass, and then the rubber solution was added to a 10L high-pressure reactor and nitrogen was introduced to remove the air in the reactor. Then, the nitrogen in the reactor was removed with hydrogen for 36 minutes, and then 0.07g of GrubbsⅠ catalyst xylene solution (mass concentration was 8%) was added under nitrogen protection. The hydrogen pressure in the pressurized reactor was 12MPa, and the temperature was raised to 113°C. After reacting for 10 hours, the system was cooled, condensed, and vacuum dried to obtain HNBR rubber (hydrogenation degree HD=87.1%).

[0077] b Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields: First, 200g HNBR rubber was dissolved in chlorobenzene solution to prepare a 7.5% glue solution by mass, and then the glue solution was added to a 10L stainless steel reactor with a jacket, and nitrogen was introduced for replacement 4 times, and then 9.0g of functionalized macromolecular long-branched grafting agent was added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reached 76°C, a mixture of 0.16g DCP and 320g chlorobenzene was added, and after reacting for 11.3 hours, it was flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields (grafting rate 3.0%). Sampling analysis: Standard samples were made, and the tested properties are shown in Table 1.

[0078] Example 5

[0079] (1) Preparation of functionalized macromolecular long-branched grafting agent:

[0080] In a 10L stainless steel polymerizer with a jacket, argon was passed through the system to replace the system 5 times, 1400g cyclohexane, 500g isoprene, and 2.3g THF were added to the polymerizer in sequence, the temperature was raised to 45°C, 127mmol n-butyl lithium was added to start the reaction, and the reaction temperature gradually increased from 45°C to 65°C within 58min to form an IR segment with a wide vinyl distribution; then the temperature was raised to 78°C, 190g 1,3-butadiene, 140g styrene, and 4.5g THF were added to the polymerizer in sequence, and the reaction was carried out for 78min to form an SBR random segment; then 90g dihydromyrcenol and 2.3g THF were added to the polymerizer and the reaction was carried out for 48min; finally, 18g The 1,3-butadiene was capped and the reaction was continued for 28 min until no free monomer was present. The gel was coagulated and dried by wet method to obtain a functional macromolecular long-branched grafting agent (Mn was 6700, Mw / Mn was 7.51).

[0081] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields:

[0082] a Preparation of hydrogenated nitrile rubber (HNBR): First, 100g of nitrile rubber 2907 was dissolved in chlorobenzene solution to prepare a 5.0% rubber solution by mass, and then the rubber solution was added to a 10L high-pressure reactor and nitrogen was introduced to remove the air in the reactor. Then, the nitrogen in the reactor was removed with hydrogen for 38 minutes, and then 0.09g of GrubbsⅠ catalyst xylene solution (mass concentration of 9%) was added under nitrogen protection. The hydrogen pressure in the pressurized reactor was 13MPa, and the temperature was raised to 117°C. After reacting for 11 hours, the system was cooled, condensed, and vacuum dried to obtain HNBR rubber (hydrogenation degree HD=88.3%).

[0083] b Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields: First, 200g HNBR rubber was dissolved in chlorobenzene solution to prepare a glue solution with a mass fraction of 8.0%, and then the glue solution was added to a 10L stainless steel reactor with a jacket, and nitrogen was introduced for replacement 5 times, and then 9.5g of functionalized macromolecular long-branched grafting agent was added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reached 78°C, a mixed solution of 0.18g DCP and 360g chlorobenzene was added. After reacting for 11.6 hours, it was flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields (grafting rate 3.1%). Sampling analysis: Standard samples were made, and the tested properties are shown in Table 1.

[0084] Example 6

[0085] (1) Preparation of functionalized macromolecular long-branched grafting agent:

[0086] In a 10L stainless steel polymerizer with a jacket, argon was passed through the system to replace the system 5 times, 1500g cyclohexane, 500g isoprene, and 2.5g THF were added to the polymerizer in sequence, the temperature was raised to 45°C, 120mmol n-butyl lithium was added to start the reaction, and the reaction temperature gradually increased from 45°C to 65°C within 60min to form an IR segment with a wide vinyl distribution; then the temperature was raised to 80°C, 200g 1,3-butadiene, 150g styrene, and 5.0g THF were added to the polymerizer in sequence, and the reaction was carried out for 80min to form an SBR random segment; then 100g dihydromyrcenol and 2.5g THF were added to the polymerizer and the reaction was carried out for 50min; finally, 20g The 1,3-butadiene was capped and the reaction was carried out for 30 minutes until no free monomer was present. The gel was coagulated and dried by wet method to obtain a functional macromolecular long-branched grafting agent (Mn was 7000, Mw / Mn was 7.86).

[0087] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields:

[0088] a Preparation of hydrogenated nitrile rubber (HNBR): First, 100g of nitrile rubber 2907 was dissolved in chlorobenzene solution to prepare a 6.0% rubber solution by mass, and then the rubber solution was added to a 10L high-pressure reactor and nitrogen was introduced to remove the air in the reactor. Then, the nitrogen in the reactor was removed by hydrogen for 40 minutes, and then 0.1g of GrubbsⅠ catalyst xylene solution (mass concentration of 10%) was added under nitrogen protection. The hydrogen pressure in the pressurized reactor was 14MPa, and the temperature was raised to 120°C. After reacting for 11 hours, the system was cooled, condensed, and vacuum dried to obtain HNBR rubber (hydrogenation degree HD=89.4%).

[0089] b Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields: First, 200g HNBR rubber was dissolved in chlorobenzene solution to prepare a 9.0% glue solution by mass, and then the glue solution was added to a 10L stainless steel reactor with a jacket, and nitrogen was introduced for replacement 5 times, and then 10g of functionalized macromolecular long-branched grafting agent was added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reached 80°C, a mixture of 0.2g DCP and 400g chlorobenzene was added. After reacting for 12 hours, it was flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields (grafting rate 3.4%). Sampling analysis: Standard samples were made, and the tested properties are shown in Table 1.

[0090] Comparative Example 1

[0091] (1) Preparation of functionalized macromolecular long-chain grafting agent: same as Example 1.

[0092] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields:

[0093] a. Preparation of hydrogenated nitrile rubber (HNBR): Same as in Example 1.

[0094] b Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields: Other conditions are the same as those in Example 1, except that the amount of functionalized macromolecular long-branched chain grafting agent added in the preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields is 4.0 g, that is: first, 200 g of HNBR rubber is dissolved in chlorobenzene solution to form a 6% glue solution by mass, and then the glue solution is added to a 10L stainless steel reactor with a jacket, and nitrogen is introduced for replacement 3 times, and then 4.0 g of functionalized macromolecular long-branched chain grafting agent is added to the reactor, stirred and mixed, heated, and a mixed solution of 0.10 g of DCP and 200 g of chlorobenzene is added when the reactor temperature reaches 70°C, and after reacting for 10.0 hours, flocculation with anhydrous ethanol is performed, washed, and dried in a 70°C oven to constant weight to obtain cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields (grafting rate 2.0%). Sampling analysis: Standard samples are prepared, and the tested performance is shown in Table 1.

[0095] Comparative Example 2

[0096] (1) Preparation of functionalized macromolecular long-branched grafting agent:

[0097] The other conditions were the same as those in Example 2, except that in the preparation process of the functionalized macromolecular long-chain branching grafting agent, the IR segments were not polymerized at variable temperatures to generate narrowly distributed IR segments, namely: in a 10L stainless steel polymerization kettle with a jacket, the system was replaced three times by passing argon gas, 1100g of cyclohexane, 500g of isoprene, and 1.3g of THF were added to the polymerization kettle in sequence, the temperature was raised to 45°C, 156mmol of n-butyl lithium was added to start the reaction, and the reaction lasted for 52min to form IR segments with narrow vinyl distribution; then the temperature was raised to 72°C, 160g of 1,3-butadiene, 110g of styrene, and 3.0g of THF were added to the polymerization kettle in sequence, the reaction lasted for 72min, and SBR random segments were formed; then 60g of dihydromyrcenol and 1.0g of THF were added to the polymerization kettle and the reaction lasted for 42min; finally, 12g of The 1,3-butadiene was capped and the reaction was continued for 22 min until no free monomer was present. The colloid was coagulated and dried by wet method to obtain a functional macromolecular long-branched grafting agent a (Mn was 5600, Mw / Mn was 4.76).

[0098] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields:

[0099] a. Preparation of hydrogenated nitrile rubber (HNBR): same as in Example 2.

[0100] b Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields: The other conditions are the same as those in Example 2, except that in the preparation process of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields, no functionalized macromolecular long-branched chain grafting agent is added, but a functionalized macromolecular long-branched chain grafting agent a is added, and the amount added is 7.0 g, that is, first, 200 g of HNBR rubber is dissolved in a chlorobenzene solution to prepare a glue solution with a mass fraction of 6.5%, and then the glue solution is added to a 10L stainless steel reactor with a jacket, and nitrogen is introduced for replacement 3 times, and then 7.0 g of functionalized macromolecular long-branched chain grafting agent a is added to the reactor, stirred and mixed, and heated. When the reactor temperature reaches 72°C, a mixed solution of 0.12 g of DCP and 260 g of chlorobenzene is added, and after reacting for 10.5 hours, it is flocculated with anhydrous ethanol, washed, and dried in an oven at 70°C to constant weight to obtain cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields (grafting rate 2.4%). Sampling and analysis: Standard samples were made and the tested properties are shown in Table 1.

[0101] Comparative Example 3

[0102] (1) Preparation of functionalized macromolecular long-branched grafting agent:

[0103] The other conditions were the same as those in Example 3, except that isoprene was not added during the preparation of the functionalized macromolecular long-branched grafting agent, that is, in a 10L stainless steel polymerizer with a jacket, the system was replaced 4 times by passing argon, 1200g of cyclohexane, 170g of 1,3-butadiene, 120g of styrene, and 3.5g of THF were added to the polymerizer in sequence, the temperature was raised to 74°C, 142mmol of n-butyl lithium was added to start the reaction for 74min to form SBR random segments; then 70g of dihydromyrcenol and 1.5g of THF were added to the polymerizer and reacted for 44min; finally, 14g of 1,3-butadiene was added to the polymerizer for end-capping, the reaction was continued for 24min until no free monomers were present, and the gel was wet-coagulated and dried to obtain a functionalized macromolecular long-branched grafting agent b (Mn was 4800, Mw / Mn was 3.14).

[0104] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields:

[0105] a. Preparation of hydrogenated nitrile rubber (HNBR): Same as Example 3.

[0106] b Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields: The other conditions are the same as those in Example 3, except that in the preparation process of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields, no functionalized macromolecular long-branched grafting agent is added, but a functionalized macromolecular long-branched grafting agent b is added in an amount of 8.0 g, that is, firstly, 200 g of HNBR rubber is dissolved in a chlorobenzene solution to prepare a glue solution with a mass fraction of 7.0%, and then the glue solution is added to a 10L stainless steel reactor with a jacket, and nitrogen is introduced for replacement 4 times, and then 8.0 g of functionalized macromolecular long-branched grafting agent b is added to the reactor, stirred and mixed, and heated. When the reactor temperature reaches 74°C, a mixed solution of 0.14 g of DCP and 290 g of chlorobenzene is added, and after reacting for 11 hours, it is flocculated with anhydrous ethanol, washed, and dried in an oven at 70°C to constant weight to obtain cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields (grafting rate 2.5%). Sampling and analysis: Standard samples were made and the tested properties are shown in Table 1.

[0107] Comparative Example 4

[0108] (1) Preparation of functionalized macromolecular long-branched grafting agent:

[0109] The other conditions were the same as those in Example 4, except that the amount of dihydromyrcenol added during the preparation of the functionalized macromolecular long-branched grafting agent was 40 g, that is, in a 10 L stainless steel polymerizer with a jacket, the system was replaced 4 times by passing argon, 1300 g cyclohexane, 500 g isoprene, and 2.0 g THF were added to the polymerizer in sequence, the temperature was raised to 45° C., 134 mmol n-butyl lithium was added to start the reaction, and the reaction temperature was gradually raised from 45° C. to 65° C. within 56 min to form an IR segment with a wide vinyl distribution; then the temperature was raised to 76° C., 180 g 1,3-butadiene, 130 g styrene, and 4.0 g THF were added to the polymerizer in sequence, and the reaction was carried out for 76 min to form an SBR random segment; then 40 g dihydromyrcenol and 2.0 g THF were added to the polymerizer and the reaction was carried out for 46 min; finally, 16 g The 1,3-butadiene was capped and the reaction was continued for 26 min until no free monomer was present. The colloid was coagulated and dried by wet method to obtain functionalized macromolecular long-branched grafting agent c (Mn was 5700, Mw / Mn was 6.98).

[0110] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields:

[0111] a Preparation of hydrogenated nitrile rubber (HNBR): same as Example 4.

[0112] b Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields: The other conditions are the same as those in Example 4, except that in the preparation process of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields, no functionalized macromolecular long-branched chain grafting agent is added, but a functionalized macromolecular long-branched chain grafting agent c is added in an amount of 9.0 g, that is, firstly, 200 g of HNBR rubber is dissolved in a chlorobenzene solution to prepare a glue solution with a mass fraction of 7.5%, and then the glue solution is added to a 10L stainless steel reactor with a jacket, and nitrogen is introduced for replacement 4 times, and then 9.0 g of functionalized macromolecular long-branched chain grafting agent c is added to the reactor, stirred and mixed, and heated. When the reactor temperature reaches 76°C, a mixed solution of 0.16 g of DCP and 320 g of chlorobenzene is added, and after reacting for 11.3 hours, it is flocculated with anhydrous ethanol, washed, and dried in an oven at 70°C to constant weight to obtain cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields (grafting rate 2.8%). Sampling and analysis: Standard samples were made and the tested properties are shown in Table 1.

[0113] Comparative Example 5

[0114] (1) Preparation of functionalized macromolecular long-branched grafting agent:

[0115] The other conditions were the same as those in Example 5, except that dihydromyrcenol was not added during the preparation of the functionalized macromolecular long-chain branching grafting agent, but 90 g of propenol was added, that is, in a 10 L stainless steel polymerizer with a jacket, the system was replaced 5 times by passing argon, 1400 g of cyclohexane, 500 g of isoprene, and 2.3 g of THF were added to the polymerizer in sequence, the temperature was raised to 45° C., 127 mmol of n-butyl lithium was added to start the reaction, and the reaction temperature was gradually raised from 45° C. to 65° C. within 58 min to form an IR segment with a wide vinyl distribution; then the temperature was raised to 78° C., 190 g of 1,3-butadiene, 140 g of styrene, and 4.5 g of THF were added to the polymerizer in sequence, and the reaction was carried out for 78 min to form an SBR random segment; then 90 g of propenol, 2.3 g of THF, react for 48 minutes; finally, add 18g 1,3-butadiene to the polymerization kettle for end-capping, and react for 28 minutes until no free monomer exists. The gel is wet-coagulated and dried to obtain a functionalized macromolecular long-branched grafting agent d (Mn is 6500, Mw / Mn is 7.42).

[0116] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields:

[0117] a Preparation of hydrogenated nitrile rubber (HNBR): same as in Example 5.

[0118] b Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields: The other conditions are the same as those in Example 5, except that in the preparation process of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields, no functionalized macromolecular long-branched chain grafting agent is added, but a functionalized macromolecular long-branched chain grafting agent d is added in an amount of 9.5 g, that is, firstly, 200 g of HNBR rubber is dissolved in a chlorobenzene solution to prepare a glue solution with a mass fraction of 8.0%, and then the glue solution is added to a 10L stainless steel reactor with a jacket, and nitrogen is introduced for replacement 5 times, and then 9.5 g of functionalized macromolecular long-branched chain grafting agent d is added to the reactor, stirred and mixed, and heated. When the reactor temperature reaches 78°C, a mixed solution of 0.18 g of DCP and 360 g of chlorobenzene is added, and after reacting for 11.6 hours, it is flocculated with anhydrous ethanol, washed, and dried in an oven at 70°C to constant weight to obtain cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields (grafting rate 2.9%). Sampling and analysis: Standard samples were made and the tested properties are shown in Table 1.

[0119] Comparative Example 6

[0120] (1) Preparation of functionalized macromolecular long-branched grafting agent:

[0121] The other conditions were the same as those in Example 6, except that 1,3-butadiene was not added during the preparation of the functionalized macromolecular long-branched grafting agent, and no SBR random segments could be generated, but PS homopolymer segments were generated, namely: in a 10L stainless steel polymerization kettle with a jacket, the system was replaced 5 times by argon, 1500g of cyclohexane, 500g of isoprene, and 2.5g of THF were added to the polymerization kettle in sequence, the temperature was raised to 45°C, 120mmol of n-butyl lithium was added to start the reaction, and the reaction temperature was gradually increased from 45°C to 65°C within 60min to form an IR segment with a wide vinyl distribution; then the temperature was raised to 80°C, 150g of styrene and 5.0g of THF were added to the polymerization kettle in sequence, and the reaction was carried out for 80min to form a PS homopolymer segment; then 100g of dihydromyrcenol and 2.5g of THF, react for 50 minutes; finally, add 20g 1,3-butadiene to the polymerization kettle for end-capping, and react for 30 minutes until no free monomer exists. The gel is wet-coagulated and dried to obtain a functionalized macromolecular long-branched grafting agent e (Mn is 58000, Mw / Mn is 5.63).

[0122] (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields:

[0123] a. Preparation of hydrogenated nitrile rubber (HNBR): Same as Example 6.

[0124] b Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields: The other conditions are the same as those in Example 6, except that in the preparation process of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields, no functionalized macromolecular long-branched chain grafting agent is added, but a functionalized macromolecular long-branched chain grafting agent e is added, and the amount of the added agent is 10 g, that is, first, 200 g of HNBR rubber is dissolved in a chlorobenzene solution to prepare a glue solution with a mass fraction of 9.0%, and then the glue solution is added to a 10L stainless steel reactor with a jacket, and nitrogen is introduced for replacement 5 times, and then 10 g of functionalized macromolecular long-branched chain grafting agent e is added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reaches 80°C, a mixed solution of 0.2 g of DCP and 400 g of chlorobenzene is added. After reacting for 12 hours, it is flocculated with anhydrous ethanol, washed, and dried in an oven at 70°C to constant weight to obtain cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields (grafting rate 3.2%). Sampling and analysis: Standard samples were made and the tested properties are shown in Table 1.

[0125] Table 1 Properties of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields

[0126]

[0127]

[0128] It can be seen from Table 1 that the cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields of the present invention has a small compression permanent deformation and a low glass transition temperature, and is suitable for oil well operations under low temperature conditions of -61°C.

[0129] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, technicians familiar with the field may make various corresponding changes and deformations based on the present invention, but these corresponding changes and deformations should all fall within the scope of protection of the present invention.

Claims

1. A method for preparing cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields, characterized in that: The steps include: (1) Preparation of functionalized macromolecular long-branched grafting agent: In a polymerization kettle, argon gas is introduced for replacement, and a solvent, isoprene, a first structural regulator, and an initiator 1 are sequentially added to the polymerization kettle. The reaction is a temperature-variable polymerization. Within 50 to 60 minutes, the temperature is gradually increased from 45° C. to 65° C. to form an IR segment with a wide vinyl distribution; then the temperature is increased to 70 to 80° C., 1,3-butadiene, styrene, and a second structural regulator are sequentially added to the polymerization kettle, and the reaction is performed for 70 to 80 minutes to form an SBR random segment; then a functional monomer dihydromyrcenol and a third structural regulator are added to the polymerization kettle, and the reaction is performed for 40 to 50 minutes; finally, 1,3-butadiene is added to the polymerization kettle for end-capping, and the reaction is performed for 20 to 30 minutes until no free monomer exists. The glue solution is subjected to wet coagulation and drying to obtain a functional macromolecular long-branch grafting agent; (2) Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields: a Preparation of hydrogenated nitrile rubber (HNBR): dissolving nitrile rubber in chlorobenzene solution to prepare a rubber solution, then adding the rubber solution into a reactor and introducing an inert gas to remove the air in the reactor, then removing the inert gas in the reactor with hydrogen, adding a xylene solution of Grubbs I catalyst under nitrogen protection, pressurizing, heating, reacting, cooling the system, condensing, and drying to obtain HNBR rubber; b. Preparation of cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields: HNBR rubber is dissolved in chlorobenzene solution to prepare a glue solution, and then the glue solution is added to a reactor, and an inert gas is introduced for replacement, and then a functionalized macromolecular long-branched grafting agent is added to the reactor, stirred and mixed, heated, and a mixed solution of initiator 2 and chlorobenzene is added. After the reaction, flocculation, washing, and drying are performed to obtain cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields; The functionalized macromolecular long-branched grafting agent has the following structure: Among them, IR is an isoprene homopolymer segment with a wide vinyl distribution; SBR is a random block copolymer segment of styrene and 1,3-butadiene; B is a terminal 1,3-butadiene, n is the number of repeating units, and n is a positive integer of ≥1; the number average molecular weight (Mn) of the functionalized macromolecular long-branched grafting agent is 5000-7000, and the molecular weight distribution (Mw / Mn) is 6.14-7.

86.

2. The preparation method according to claim 1, characterized in that: The initiator 1 is selected from one of n-butyl lithium, sec-butyl lithium, methylbutyl lithium, phenylbutyl lithium, naphthalene lithium, cyclohexyl lithium and dodecyl lithium.

3. The preparation method according to claim 1, characterized in that: The initiator 2 is selected from one of diacetyl peroxide, diisobutyryl peroxide, cumene hydroperoxide, dicumyl peroxide (DCP) and dibenzoyl peroxide, and its addition amount is 0.05-0.3 parts based on 100 parts of the mass of the HNBR rubber.

4. The preparation method according to claim 1, characterized in that: The nitrile rubber is copolymerized by emulsion polymerization of 1,3-butadiene and acrylonitrile, and the acrylonitrile content of the nitrile rubber is 20wt% to 42wt%.

5. The preparation method according to claim 1, characterized in that: The structure regulator is selected from one of diethylene glycol dimethyl ether (2G), tetrahydrofuran (THF), ethyl ether, ethyl methyl ether, anisole, diphenyl ether, ethylene glycol dimethyl ether (DME), and triethylamine.

6. The preparation method according to claim 1, characterized in that: The solvent is selected from one of cyclohexane, carbon disulfide (CS2), nitrobenzene, petroleum ether, tetrachloroethane, toluene and xylene.

7. The preparation method according to claim 1, characterized in that: In the step (1), during the formation of the SBR random segments, the mass ratio of the solvent, isoprene, structure regulator, 1,3-butadiene, styrene, and the second structure regulator is 200-300:100:0.2-0.5:30-40:20-30:0.5-1.0; In the end-capping process, the mass ratio of the dihydromyrcenol, the third structural regulator, and 1,3-butadiene is 10-20:0.1-0.5:2-4.

8. The preparation method according to claim 1, characterized in that: In step (2) a, the mass ratio of the nitrile rubber to the Grubbs I catalyst is 100:0.02-0.

1.

9. The preparation method according to claim 1, characterized in that: In step (2) a, the degree of hydrogenation HD of the HNBR rubber is less than 90%.

10. The preparation method according to claim 1, characterized in that: In step (2) b, the mass ratio of the HNBR rubber, the functionalized macromolecular long-chain branching grafting agent, and chlorobenzene is 100:3-5:100-200.

11. The preparation method according to claim 1, characterized in that: In step (2) b, the grafting rate of the cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields is 2.3% to 3.4%.

12. A cold-resistant and compression-resistant hydrogenated nitrile rubber for oil fields obtained by the preparation method according to any one of claims 1 to 11.

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