Deformation-resistant low-temperature-grade hydrogenated butadiene-acrylonitrile rubber and preparation method thereof

Abstract

The invention discloses a deformation-resistant low-temperature-grade hydrogenated nitrile rubber and a preparation method thereof, the preparation method comprises: (1) preparation of a macromolecular long-branch-chain grafting agent and (2) preparation of deformation-resistant low-temperature-grade hydrogenated nitrile rubber, the macromolecular long-branch-chain grafting agent has the following structure: # imgabs0 #, BR is a 1, 3-butadiene homopolymer segment, R is a C6-C12 straight-chain alkyl group, and the macromolecular long-branch-chain grafting agent has the following structure: 1, 3-butadiene-styrene-butadiene-acrylonitrile copolymer; m and n are repetitive unit numbers, n is a positive integer greater than or equal to 1, and m is a positive integer greater than or equal to 1; the number-average molecular weight (Mn) of the macromolecular long-chain grafting agent is 7000 to 9000. The preparation method of the deformation-resistant and low-temperature-grade hydrogenated nitrile rubber has the characteristics of environment friendliness, efficient and stable modification effect, low addition proportion, 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 deformation-resistant, low-temperature grade hydrogenated nitrile rubber modified by a macromolecular unsaturated long-chain branching 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 deformation-resistant, low-temperature grade hydrogenated nitrile rubber with a compression set resistance of ≤28% and a glass transition temperature Tg<-55°C, which can meet the use requirements within the range of -55°C to -57°C. The invention firstly synthesizes a homopolymer containing unsaturated double bonds by an anionic polymerization method, and then prepares a macromolecular long-chain grafting agent with free radical reaction activity with ethylene under the action of a reaction monomer long-chain α-olefin under the action of a nickel-based complex catalyst; finally, the macromolecular long-chain grafting agent is grafted onto the main chain of hydrogenated nitrile rubber to prepare a deformation-resistant, low-temperature grade hydrogenated nitrile rubber for oil fields. The method solves the problem of easy crystallization of hydrogenated nitrile rubber, so that the hydrogenated nitrile rubber not only shows very excellent low-temperature properties, but also maintains sufficient deformation resistance, and achieves a balance between the low-temperature properties and deformation resistance of hydrogenated nitrile rubber. It is very suitable for oil well operations under working temperatures of -55°C and compression set resistance of ≤28%.

[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 a deformation-resistant, low-temperature grade hydrogenated nitrile rubber, the preparation process comprising the following steps:

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

[0011] a Preparation of 1,3-butadiene homopolymer (BR): In a polymerization kettle, argon gas is introduced for replacement, and solvent, 1,3-butadiene, structure regulator, and initiator 1 are added to the polymerization kettle in sequence, and the temperature is raised to react until no free monomer exists. The rubber solution is wet-coagulated and dried to obtain a BR homopolymer;

[0012] b. Preparation of macromolecular long-chain branching grafting agent: inert gas is introduced into the reactor for replacement, solvent is added, the temperature is increased, and alkylaluminoxane co-catalyst is added under stirring, and stirring is continued under the protection of inert gas; then BR homopolymer and solution are mixed and stirred to dissolve, and after complete dissolution, they are added into the autoclave together with long-chain α-olefin and nickel-based complex catalyst, and ethylene is introduced at this time for reaction; after the reaction is completed, the macromolecular long-chain branching grafting agent is obtained by centrifugal separation and drying;

[0013] (2) Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile rubber:

[0014] a Preparation of hydrogenated nitrile rubber (HNBR): First, the nitrile rubber is dissolved in a chlorobenzene solution to prepare a rubber solution, and then the rubber solution is added to a reactor and an inert gas is introduced to remove the air in the reactor. Then, the inert gas in the reactor is removed with hydrogen, and then a xylene solution of Grubbs I catalyst is added under nitrogen protection, pressurized, heated, reacted, the system is cooled, condensed, and vacuum dried to obtain HNBR rubber;

[0015] b. Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile rubber: 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 macromolecular long-branched chain grafting agent is added to the reactor, stirred and mixed, heated, and a mixed solution of initiator 2 and chlorobenzene is added to react, flocculated with anhydrous ethanol, washed, and dried to obtain a deformation-resistant, low-temperature grade hydrogenated nitrile rubber;

[0016] The macromolecular long-branched grafting agent has the following structure:

[0017]

[0018] Among them, BR is 1,3-butadiene homopolymer segment, R is C 6 ~C 12 m and n are the number of repeating units, n≥1, and m≥1; the number average molecular weight (Mn) of the macromolecular long chain grafting agent is 7000-9000.

[0019] The long-chain α-olefin described in the present invention is a C 6 ~C 12 The straight-chain olefin may be selected from one of 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene and 1-dodecene, preferably 1-octene.

[0020] The nickel-based complex catalyst of the present invention is selected from one of (1-naphthyl)〔8-(diphenylphosphino)quinoline〕nickel chloride, trans-phenyl(bis(triphenylphosphine))nickel bromide and 2,5-diformylpyrrolenickel dibromide, preferably trans-phenyl(bis(triphenylphosphine))nickel bromide.

[0021] The alkylaluminoxane cocatalyst of the present invention is selected from one of methylaluminoxane (MAO) and ethylaluminoxane (EAO), preferably methylaluminoxane.

[0022] 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.

[0023] 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 0.01 to 0.1 parts, preferably 0.04 to 0.06 parts, based on 100 parts by mass of the HNBR rubber.

[0024] 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%.

[0025] 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).

[0026] The solvent or solution of the present invention can be selected from cyclohexane, carbon disulfide (CS 2 ), one of nitrobenzene, petroleum ether, tetrachloroethane, toluene, and xylene, preferably cyclohexane.

[0027] In step (1) a of the present invention, the mass ratio of the solvent, 1,3-butadiene and structure regulator is 2-4:1:0.005-0.01.

[0028] In step (1) a of the present invention, the temperature is raised to 50-60° C. and the reaction time is 60-70 min.

[0029] In step (1) b of the present invention, the mass ratio of the solvent, the alkylaluminoxane cocatalyst, the BR homopolymer, the solution, the long-chain α-olefin, and the nickel-based complex catalyst is 400-500:20-30:3.0-5.0:100-200:10-20:1.

[0030] In step (1) b of the present invention, the temperature is raised to 80-90°C, the stirring speed is 700-800 rpm, the stirring is continued for 20-30 min, the stirring and dissolving time is 30-50 min, the reaction pressure is 15-20 MPa, and the reaction time is 4.0-6.0 hr.

[0031] In step (2) a of the present invention, based on 100 parts by mass of the nitrile rubber, the mass ratio of the nitrile rubber to the Grubbs I catalyst is 100:0.02-0.1; and the degree of hydrogenation HD of the HNBR rubber is less than 90%.

[0032] In step (2) a of the present invention, the mass fraction of the glue solution is 3% to 6%.

[0033] In step (2) a of the present invention, the mass concentration of the xylene solution of the Grubbs I catalyst is 5% to 10%.

[0034] In step (2) a of the present invention, the pressure is increased to 11-14 MPa; the temperature is increased to 100-120° C., and the reaction time is 9-11 hr.

[0035] In step (2) b of the present invention, the mass ratio of the HNBR rubber, the macromolecular long-chain branching grafting agent, and chlorobenzene is 100:3-5:100-200.

[0036] In step (2) b of the present invention, the mass concentration of HNBR rubber in the rubber solution is 6% to 9%.

[0037] In step (2) b of the present invention, the heating temperature is 80 to 90° C. and the reaction time is 8.0 to 9.0 hr.

[0038] In step (2) b of the present invention, the grafting rate of the deformation-resistant, low-temperature grade hydrogenated nitrile rubber is 2.9% to 3.7%.

[0039] 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.

[0040] The reactor of the present invention can be a loop reactor or a tank reactor, preferably a tank reactor.

[0041] 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.

[0042] The present invention also provides a deformation-resistant, low-temperature grade hydrogenated nitrile rubber obtained by the above preparation method.

[0043] Compared with the prior art, the present invention has at least the following advantages and beneficial effects:

[0044] (1) The macromolecular long-chain branching grafting agent prepared by the present invention synthesizes 1,3-butadiene homopolymer by anionic polymerization, and then synthesizes a macromolecular long-chain branching agent with a long-chain α-olefin by coordination polymerization. The macromolecular long-chain branching agent is activated by ethylene to have free radical reaction activity and can be grafted onto hydrogenated nitrile rubber, thereby forming a long-chain branching structure containing unsaturated double bonds on the main chain structure of hydrogenated nitrile rubber. This structure organically combines the long-chain branching structure and the unsaturated double bond structure into a whole, thereby achieving a good "synergistic effect" in reducing the crystallinity of HNBR and the viscoelasticity of HNBR. The glass transition temperature (Tg) of HNBR can be greatly reduced with a low addition amount, and the compression set resistance of HNBR can be significantly improved, thereby preparing a deformation-resistant, low-temperature grade hydrogenated nitrile rubber with a compression set resistance of ≤28% and a glass transition temperature Tg<-55°C.

[0045] (2) The deformation-resistant, low-temperature grade hydrogenated nitrile rubber prepared by the present invention fully utilizes the "stacking effect" and "group effect" of the long-chain branch structure and the unsaturated double bonds under the condition of ensuring a certain degree of hydrogenation, thereby achieving a balance between the low temperature property and deformation resistance of the hydrogenated nitrile rubber, and is suitable for oil well operations under low temperature conditions of -55°C.

[0046] (3) The preparation method of the deformation-resistant, low-temperature grade hydrogenated nitrile rubber of the present invention is green and environmentally friendly, has efficient and stable modification effect, has a low addition ratio, and has readily available raw materials on the market, and is suitable for industrial production. DETAILED DESCRIPTION

[0047] 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.

[0048] (1) Source of raw materials:

[0049]

[0050] (2) Analytical testing methods:

[0051] 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:

[0052]

[0053] Where: m 0 —Total mass of glue (g); m—Mass of sample weighed after reaction (g); m m —Total mass of monomers in the reactants (g); m HNBR —Mass of hydrogenated nitrile rubber in the sample (g); m 1 —The mass of the sample after extraction (g).

[0054] 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 .

[0055] Determination of HNBR hydrogenation degree: Using nuclear magnetic resonance hydrogen spectrum ( 1 The 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:

[0056] Degree of hydrogenation HD (%) = 1-unsaturation (U)

[0057] 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.

[0058] Compression set: Execute the method in standard GB / T 7759.1-2015.

[0059] Example 1

[0060] (1) Preparation of macromolecular long-branched grafting agent:

[0061] a Preparation of 1,3-butadiene homopolymer (BR): In a 10L stainless steel polymerizer with a jacket, the system was replaced three times with argon, 1000g cyclohexane, 500g 1,3-butadiene, 2.5g THF, and 171mmol n-butyl lithium were added to the polymerizer in sequence, the temperature was raised to 50°C, and the reaction was carried out for 60min until no free monomer was present. The colloid was wet-coagulated and dried to obtain a BR homopolymer.

[0062] b. Preparation of macromolecular long-chain branching grafting agent: First, nitrogen was replaced three times in a 10L autoclave, 4000g of cyclohexane was added, and the temperature was raised to 80°C. Then, 200g of methylaluminoxane co-catalyst was gradually added dropwise under uniform stirring at a speed of 700rpm, and stirring was continued for 20min under the protection of nitrogen gas. Subsequently, 30g of BR homopolymer and 1000g of cyclohexane were mixed and stirred to dissolve for 30min, and then added into the autoclave together with 100g of 1-octene and 10g of trans-bromphenyl (bis(triphenylphosphine)) nickel main catalyst, ethylene was introduced, and the pressure was maintained at 15MPa for reaction for 4.0hr; after the reaction was completed, the macromolecular long-chain branching grafting agent (number average molecular weight Mn was 7000) was obtained by centrifugation and drying.

[0063] (2) Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile rubber:

[0064] a Preparation of hydrogenated nitrile rubber (HNBR): First, 100g of nitrile rubber 2707 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%).

[0065] b. Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile rubber: First, 200g of 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 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 mixed solution of 0.08g of DCP and 200g of chlorobenzene was added, and after reacting for 8.0 hours, it was flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain deformation-resistant, low-temperature grade hydrogenated nitrile rubber (grafting rate 2.9%). Sampling analysis: Standard samples were made, and the tested properties are shown in Table 1.

[0066] Example 2

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

[0068] a Preparation of 1,3-butadiene homopolymer (BR): In a 10L stainless steel polymerizer with a jacket, the system was replaced three times with argon, 1300g cyclohexane, 500g 1,3-butadiene, 3.0g THF, and 182mmol n-butyl lithium were added to the polymerizer in sequence, the temperature was raised to 52°C, and the reaction was carried out for 62min until no free monomer was present. The colloid was wet-coagulated and dried to obtain a BR homopolymer.

[0069] b. Preparation of macromolecular long-chain branching grafting agent: First, nitrogen was replaced three times in a 10L autoclave, 4200g of cyclohexane was added, and the temperature was raised to 82°C. Then, 210g of methylaluminoxane co-catalyst was gradually added dropwise under uniform stirring at a speed of 720rpm, and stirring was continued for 22min under the protection of nitrogen gas. Subsequently, 35g of BR homopolymer and 1200g of cyclohexane were mixed and stirred to dissolve for 35min, and then added into the autoclave together with 120g of 1-octene and 10g of trans-bromphenyl (bis(triphenylphosphine)) nickel main catalyst, ethylene was introduced, and the pressure was maintained at 16MPa for reaction for 4.5hr; after the reaction was completed, the macromolecular long-chain branching grafting agent (number average molecular weight Mn was 7300) was obtained by centrifugation and drying.

[0070] (2) Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile rubber:

[0071] a Preparation of hydrogenated nitrile rubber (HNBR): First, 100g of nitrile rubber 2707 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%).

[0072] b. Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile rubber: First, 200g of 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 a macromolecular long-branched grafting agent was added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reached 82°C, a mixed solution of 0.09g of DCP and 240g of chlorobenzene was added, and after reacting for 8.2 hours, it was flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain deformation-resistant, low-temperature grade hydrogenated nitrile rubber (grafting rate 3.0%). Sampling analysis: Standard samples were made, and the tested properties are shown in Table 1.

[0073] Example 3

[0074] (1) Preparation of macromolecular long-branched grafting agent:

[0075] a Preparation of 1,3-butadiene homopolymer (BR): In a 10L stainless steel polymerizer with a jacket, the system was replaced 4 times with argon, 1500g cyclohexane, 500g 1,3-butadiene, 3.5g THF, 191mmol n-butyl lithium were added to the polymerizer in sequence, the temperature was raised to 54°C, and the reaction was carried out for 64min until no free monomer was present. The colloid was wet-coagulated and dried to obtain BR homopolymer.

[0076] b. Preparation of macromolecular long-chain branching grafting agent: First, nitrogen was replaced in a 10L autoclave for 4 times, 4400g of cyclohexane was added, and the temperature was raised to 84°C. Then, 230g of methylaluminoxane co-catalyst was gradually added dropwise under uniform stirring at a speed of 740rpm, and stirring was continued for 24min under the protection of nitrogen gas. Subsequently, 40g of BR homopolymer and 1400g of cyclohexane were mixed and stirred to dissolve for 40min, and then added into the autoclave together with 150g of 1-octene and 10g of trans-bromphenyl (bis(triphenylphosphine)) nickel main catalyst, ethylene was introduced, and the pressure was maintained at 17MPa for reaction for 5.0hr; after the reaction was completed, centrifugal separation and drying were carried out to obtain a macromolecular long-chain branching grafting agent (number average molecular weight Mn was 7800).

[0077] (2) Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile rubber:

[0078] a Preparation of hydrogenated nitrile rubber (HNBR): First, 100g of nitrile rubber 2707 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%).

[0079] b. Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile rubber: 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 macromolecular long-branched grafting agent was added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reached 84°C, a mixed solution of 0.1g DCP and 300g chlorobenzene was added, and after reacting for 8.4 hours, it was flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain deformation-resistant, low-temperature grade hydrogenated nitrile rubber (grafting rate 3.2%). Sampling analysis: Standard samples were made, and the tested properties are shown in Table 1.

[0080] Example 4

[0081] (1) Preparation of macromolecular long-branched grafting agent:

[0082] a Preparation of 1,3-butadiene homopolymer (BR): In a 10L stainless steel polymerizer with a jacket, the system was replaced 4 times with argon, 1700g cyclohexane, 500g 1,3-butadiene, 4.0g THF, and 210mmol n-butyl lithium were added to the polymerizer in sequence, the temperature was raised to 56°C, and the reaction was carried out for 66min until no free monomer was present. The colloid was wet-coagulated and dried to obtain a BR homopolymer.

[0083] b. Preparation of macromolecular long-chain branching grafting agent: First, nitrogen was replaced in a 10L autoclave for 4 times, 4600g of cyclohexane was added, and the temperature was raised to 86°C. Then, 260g of methylaluminoxane co-catalyst was gradually added dropwise under uniform stirring at a speed of 760rpm, and stirring was continued for 26min under the protection of nitrogen gas. Subsequently, 43g of BR homopolymer and 1600g of cyclohexane were mixed and stirred to dissolve for 44min, and then added into the autoclave together with 160g of 1-octene and 10g of trans-bromophenyl (bis(triphenylphosphine)) nickel main catalyst, ethylene was introduced, and the pressure was maintained at 18MPa for reaction for 5.3hr; after the reaction was completed, the macromolecular long-chain branching grafting agent (number average molecular weight Mn was 8200) was obtained by centrifugation and drying.

[0084] (2) Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile rubber:

[0085] a Preparation of hydrogenated nitrile rubber (HNBR): First, 100g of nitrile rubber 2707 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 of 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%).

[0086] b. Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile rubber: 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 4 times, and then 8.5g of a macromolecular long-branched grafting agent was added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reached 86°C, a mixed solution of 0.1g DCP and 300g chlorobenzene was added. After reacting for 8.6 hours, it was flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain deformation-resistant, low-temperature grade hydrogenated nitrile rubber (grafting rate 3.5%). Sampling analysis: Standard samples were made, and the tested properties are shown in Table 1.

[0087] Example 5

[0088] (1) Preparation of macromolecular long-branched grafting agent:

[0089] a Preparation of 1,3-butadiene homopolymer (BR): In a 10L stainless steel polymerizer with a jacket, the system was replaced 5 times with argon, 1900g cyclohexane, 500g 1,3-butadiene, 4.5g THF, and 230mmol n-butyl lithium were added to the polymerizer in sequence, the temperature was raised to 58°C, and the reaction was carried out for 68min until no free monomer was present. The colloid was wet-coagulated and dried to obtain a BR homopolymer.

[0090] b. Preparation of macromolecular long-chain branching grafting agent: First, nitrogen was replaced in a 10L autoclave for 5 times, 4800g of cyclohexane was added, and the temperature was raised to 88°C. Then, 280g of methylaluminoxane co-catalyst was gradually added dropwise under uniform stirring at a speed of 780rpm, and stirring was continued for 28min under the protection of nitrogen gas. Subsequently, 47g of BR homopolymer and 1800g of cyclohexane were mixed and stirred to dissolve for 47min, and then added into the autoclave together with 180g of 1-octene and 10g of trans-bromophenyl (bis(triphenylphosphine)) nickel main catalyst, ethylene was introduced, and the pressure was maintained at 19MPa for reaction for 5.6hr; after the reaction was completed, centrifugal separation and drying were carried out to obtain a macromolecular long-chain branching grafting agent (number average molecular weight Mn was 8400).

[0091] (2) Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile rubber:

[0092] a Preparation of hydrogenated nitrile rubber (HNBR): First, 100g of nitrile rubber 2707 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%).

[0093] b. Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile rubber: First, 200g of 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 9.0g of a macromolecular long-branched grafting agent was added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reached 88°C, a mixed solution of 0.11g of DCP and 350g of chlorobenzene was added. After reacting for 8.8 hours, it was flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain deformation-resistant, low-temperature grade hydrogenated nitrile rubber (grafting rate 3.6%). Sampling analysis: Standard samples were made, and the tested properties are shown in Table 1.

[0094] Example 6

[0095] (1) Preparation of macromolecular long-branched grafting agent:

[0096] a Preparation of 1,3-butadiene homopolymer (BR): In a 10L stainless steel polymerizer with a jacket, the system was replaced 5 times with argon, 2000g cyclohexane, 500g 1,3-butadiene, 5.0g THF, and 260mmol n-butyl lithium were added to the polymerizer in sequence, the temperature was raised to 60°C, and the reaction was carried out for 70min until no free monomer was present. The colloid was wet-coagulated and dried to obtain BR homopolymer.

[0097] b. Preparation of macromolecular long-chain branching grafting agent: First, nitrogen was replaced in a 10L autoclave for 5 times, 5000g of cyclohexane was added, and the temperature was raised to 90°C. Then, 300g of ethylaluminoxane co-catalyst was gradually added dropwise under uniform stirring at a speed of 800rpm, and stirring was continued for 30min under the protection of nitrogen gas. Subsequently, 50g of BR homopolymer and 2000g of cyclohexane were mixed and stirred to dissolve for 50min, and then added into the autoclave together with 200g of 1-hexene and 10g of 2,5-diformylpyrrole nickel dibromide main catalyst, ethylene was introduced, and the pressure was maintained at 20MPa for reaction for 6.0hr; after the reaction was completed, centrifugal separation and drying were performed to obtain a macromolecular long-chain branching grafting agent (number average molecular weight Mn was 9000).

[0098] (2) Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile rubber:

[0099] a Preparation of hydrogenated nitrile rubber (HNBR): First, 100g of nitrile rubber 2707 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 with 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%).

[0100] b. Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile rubber: First, 200g of 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 10.0g of a macromolecular long-branched grafting agent was added to the reactor, stirred and mixed, and heated. When the temperature of the reactor reached 90°C, a mixed solution of 0.12g of DCP and 400g of chlorobenzene was added, and after reacting for 9.0 hours, it was flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain deformation-resistant, low-temperature grade hydrogenated nitrile rubber (grafting rate 3.7%). Sampling analysis: Standard samples were made, and the tested properties are shown in Table 1.

[0101] Comparative Example 1

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

[0103] a Preparation of 1,3-butadiene homopolymer (BR): Same as Example 1.

[0104] b. Preparation of macromolecular long-chain branching grafting agent: Other conditions are the same as those in Example 1, except that the amount of BR homopolymer added in the preparation of macromolecular long-chain branching grafting agent is 20 g, that is, first, nitrogen is passed through a 10L autoclave for replacement three times, 4000 g of cyclohexane is added, the temperature is raised to 80°C, 200 g of methylaluminoxane co-catalyst is gradually added dropwise under uniform stirring at a speed of 700 rpm, and stirring is continued for 20 min under the protection of nitrogen gas, then 20 g of BR homopolymer and 1000 g of cyclohexane are mixed and stirred to dissolve for 30 min, and then added into the autoclave together with 100 g of 1-octene and 10 g of trans-bromophenyl (bis(triphenylphosphine)) nickel main catalyst, ethylene is passed through, and the pressure is maintained at 15 MPa for reaction for 4.0 hr; after the reaction is completed, the macromolecular long-chain branching grafting agent a (number average molecular weight Mn is 6100) is obtained by centrifugation and drying.

[0105] (2) Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile rubber:

[0106] a. Preparation of hydrogenated nitrile rubber (HNBR): Same as in Example 1.

[0107] b. Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile rubber: Other conditions are the same as those in Example 1, except that in the preparation process of deformation-resistant, low-temperature grade hydrogenated nitrile rubber, no macromolecular long-branched chain grafting agent is added, but macromolecular long-branched chain grafting agent a is added, and the addition amount is 6.0g, that is: first, 200g HNBR rubber is dissolved in chlorobenzene solution to form a glue solution with a mass fraction of 6%, 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 6.0g macromolecular long-branched chain grafting agent a is added to the reactor, stirred and mixed, heated, and when the reactor temperature reaches 80°C, a mixed solution of 0.08g DCP and 200g chlorobenzene is added, and after reacting for 8.0hr, it is flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain deformation-resistant, low-temperature grade hydrogenated nitrile rubber (grafting rate 2.4%). Sampling analysis: Standard samples are made, and the tested properties are shown in Table 1.

[0108] Comparative Example 2

[0109] (1) Preparation of macromolecular long-branched grafting agent:

[0110] The other conditions are the same as those in Example 2, except that BR homopolymer is not added during the preparation of the deformation-resistant, low-temperature grade hydrogenated nitrile rubber, but 1,3-butadiene is added in an amount of 35 g, that is: first, nitrogen is passed through a 10L autoclave for replacement three times, 4200 g of cyclohexane is added, and the temperature is raised to 82°C. Then, 210 g of methylaluminoxane co-catalyst is gradually added dropwise under uniform stirring at a speed of 720 rpm, and stirring is continued for 22 min under nitrogen gas protection, and then 35 g of 1,3-butadiene and 1200 g of cyclohexane are mixed and stirred to dissolve for 35 min, and then added to the autoclave together with 120 g of 1-octene and 10 g of trans-brominated phenyl (bis (triphenylphosphine)) nickel main catalyst, ethylene is passed, and the pressure is maintained at 16 MPa for reaction for 4.5 hr; after the reaction is completed, it is centrifuged and dried to obtain a macromolecular long-branched grafting agent b (number average molecular weight Mn is 6400).

[0111] (2) Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile rubber:

[0112] a. Preparation of hydrogenated nitrile rubber (HNBR): same as in Example 2.

[0113] b. Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile rubber: Other conditions are the same as those in Example 2, except that no macromolecular long-branched grafting agent is added during the preparation of deformation-resistant, low-temperature grade hydrogenated nitrile rubber, but a macromolecular long-branched grafting agent b 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 form a 6.5% 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 7.0 g of macromolecular long-branched grafting agent b is added to the reactor, stirred and mixed, heated, and a mixed solution of 0.09 g of DCP and 240 g of chlorobenzene is added when the reactor temperature reaches 82°C, and after reacting for 8.2 hours, anhydrous ethanol is used for flocculation, washing, and drying in a 70°C oven to constant weight to obtain deformation-resistant, low-temperature grade hydrogenated nitrile rubber (grafting rate 2.7%). Sampling analysis: Standard samples are made, and the tested performance is shown in Table 1.

[0114] Comparative Example 3

[0115] (1) Preparation of macromolecular long-branched grafting agent:

[0116] a Preparation of 1,3-butadiene homopolymer (BR): Same as Example 3.

[0117] b. Preparation of macromolecular long-chain branching grafting agent: Other conditions were the same as those in Example 3, except that 1-octene was not added during the preparation of the macromolecular long-chain branching grafting agent, but 1-butene was added in an amount of 150 g, namely: first, nitrogen was passed through a 10L autoclave for replacement 4 times, 4400 g of cyclohexane was added, and after the temperature was raised to 84°C, 230 g of methylaluminoxane co-catalyst was gradually added dropwise under uniform stirring at a speed of 740 rpm, and stirring was continued for 24 min under the protection of nitrogen gas, and then 40 g of BR homopolymer and 1400 g of cyclohexane were mixed and stirred to dissolve for 40 min, and then added into the autoclave together with 150 g of 1-butene and 10 g of trans-bromophenyl (bis(triphenylphosphine)) nickel main catalyst, ethylene was passed through, and the pressure was maintained at 17 MPa for reaction for 5.0 hr; after the reaction was completed, the macromolecular long-chain branching grafting agent c (number average molecular weight Mn was 6800) was obtained by centrifugation and drying.

[0118] (2) Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile rubber:

[0119] a. Preparation of hydrogenated nitrile rubber (HNBR): Same as Example 3.

[0120] b. Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile rubber: Other conditions are the same as those in Example 3, except that in the preparation process of deformation-resistant, low-temperature grade hydrogenated nitrile rubber, no macromolecular long-branched chain grafting agent is added, but macromolecular long-branched chain grafting agent c is added, and the addition amount is 8.0g, that is: first, 200g HNBR rubber is dissolved in chlorobenzene solution to form 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 8.0g of macromolecular long-branched chain grafting agent c is added to the reactor, stirred and mixed, heated, and a mixed solution of 0.1g DCP and 300g chlorobenzene is added when the reactor temperature reaches 84°C. After reacting for 8.4hr, it is flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain deformation-resistant, low-temperature grade hydrogenated nitrile rubber (grafting rate 3.0%). Sampling analysis: Standard samples are made, and the tested performance is shown in Table 1.

[0121] Comparative Example 4

[0122] (1) Preparation of macromolecular long-branched grafting agent:

[0123] a Preparation of 1,3-butadiene homopolymer (BR): Same as Example 4.

[0124] b. Preparation of macromolecular long-chain branching grafting agent: Other conditions are the same as those in Example 4, except that the amount of trans-brominated phenyl (bis (triphenylphosphine)) nickel main catalyst added in the preparation of macromolecular long-chain branching grafting agent is 5.0 g, that is: first, nitrogen is passed through a 10L autoclave for replacement 4 times, 4600g of cyclohexane is added, and after the temperature is raised to 86°C, 260g of methylaluminoxane co-catalyst is gradually added dropwise under uniform stirring at a speed of 760rpm, and stirring is continued for 26min under nitrogen gas protection, then 43g of BR homopolymer and 1600g of cyclohexane are mixed and stirred to dissolve for 44min, and then added into the autoclave together with 160g of 1-octene and 5.0g of trans-brominated phenyl (bis (triphenylphosphine)) nickel main catalyst, ethylene is passed through, and the pressure is maintained at 18MPa for reaction for 5.3hr; after the reaction is completed, centrifugal separation and drying are carried out to obtain macromolecular long-chain branching grafting agent d (number average molecular weight Mn is 4300).

[0125] (2) Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile rubber:

[0126] a Preparation of hydrogenated nitrile rubber (HNBR): same as Example 4.

[0127] b. Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile rubber: Other conditions are the same as those in Example 4, except that in the preparation process of deformation-resistant, low-temperature grade hydrogenated nitrile rubber, no macromolecular long-branched chain grafting agent is added, but macromolecular long-branched chain grafting agent d is added, and the addition amount is 8.5g, that is: first, 200g HNBR rubber is dissolved in chlorobenzene solution to form 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 4 times, and then 8.5g of macromolecular long-branched chain grafting agent d is added to the reactor, stirred and mixed, heated, and a mixed solution of 0.1g DCP and 300g chlorobenzene is added when the reactor temperature reaches 86°C. After reacting for 8.6 hours, it is flocculated with anhydrous ethanol, washed, and dried in a 70°C oven to constant weight to obtain deformation-resistant, low-temperature grade hydrogenated nitrile rubber (grafting rate 3.1%). Sampling analysis: Standard samples are made, and the tested performance is shown in Table 1.

[0128] Comparative Example 5

[0129] (1) Preparation of macromolecular long-branched grafting agent:

[0130] a Preparation of 1,3-butadiene homopolymer (BR): Same as Example 5.

[0131] b. Preparation of macromolecular long-branched grafting agent: same as Example 5.

[0132] (2) Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile rubber:

[0133] Preparation of a hydrogenated nitrile rubber (HNBR): Other conditions were the same as those in Example 5, except that the amount of GrubbsⅠ catalyst xylene solution (mass concentration of 9%) added during the preparation of hydrogenated nitrile rubber (HNBR) was 0.2 g, namely: first, 100 g of nitrile rubber 2707 was dissolved in chlorobenzene solution to form a 5.0% glue solution by mass, then the glue solution was added to a 10 L autoclave and nitrogen was introduced to remove the air in the autoclave, then the nitrogen in the autoclave was removed with hydrogen for 38 min, and then 0.2 g of GrubbsⅠ catalyst xylene solution (mass concentration of 9%) was added under nitrogen protection, the hydrogen pressure in the pressurized autoclave was 13 MPa, the temperature was raised to 117° C., and after the reaction for 11 hours, the system was cooled, condensed, and vacuum dried to obtain HNBR rubber b (degree of hydrogenation HD=92.3%).

[0134] b. Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile rubber: Other conditions are the same as those in Example 5, except that HNBR rubber is not added in the preparation process of deformation-resistant, low-temperature grade hydrogenated nitrile rubber, but HNBR rubber b is added in an amount of 200g, that is: first, 200g of HNBR rubber b is dissolved in chlorobenzene solution to form 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 9.0g of a macromolecular long-branched chain grafting agent is added to the reactor, stirred and mixed, heated, and a mixed solution of 0.11g DCP and 350g chlorobenzene is added when the reactor temperature reaches 88°C, and after reacting for 8.8hr, anhydrous ethanol is used for flocculation, washing, and drying in a 70°C oven to constant weight to obtain deformation-resistant, low-temperature grade hydrogenated nitrile rubber (grafting rate 1.6%). Sampling analysis: Standard samples are made, and the tested performance is shown in Table 1.

[0135] Comparative Example 6

[0136] (1) Preparation of macromolecular long-branched grafting agent:

[0137] a Preparation of 1,3-butadiene homopolymer (BR): Same as Example 6.

[0138] b. Preparation of macromolecular long-branched grafting agent: same as Example 6.

[0139] (2) Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile rubber:

[0140] a. Preparation of hydrogenated nitrile rubber (HNBR): Same as Example 6.

[0141] b. Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile rubber: Other conditions are the same as those in Example 6, except that the amount of macromolecular long-branched grafting agent added during the preparation of deformation-resistant, low-temperature grade hydrogenated nitrile rubber is 4.0 g, that is, first, 200 g of HNBR rubber is dissolved in chlorobenzene solution to form a 9.0% glue solution by mass, then the glue solution is added to a 10L stainless steel reactor with a jacket, nitrogen is introduced for replacement 5 times, and then 4.0 g of macromolecular long-branched grafting agent is added to the reactor, stirred and mixed, heated, and a mixed solution of 0.12 g of DCP and 400 g of chlorobenzene is added when the reactor temperature reaches 90°C. After reacting for 9.0 hours, anhydrous ethanol is used for flocculation, washing, and drying in a 70°C oven to constant weight to obtain deformation-resistant, low-temperature grade hydrogenated nitrile rubber (grafting rate 3.5%). Sampling analysis: Standard samples are made, and the tested properties are shown in Table 1.

[0142] Table 1 Properties of deformation-resistant and low-temperature grade hydrogenated nitrile rubber

[0143]

[0144]

[0145] It can be seen from Table 1 that the deformation-resistant, low-temperature grade hydrogenated nitrile rubber of the present invention has a small compression permanent deformation and a low glass transition temperature and is suitable for oil well operations under working temperatures of -55°C and compression permanent deformation resistance ≤ 28%.

[0146] 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 a deformation-resistant, low-temperature grade hydrogenated nitrile rubber, characterized in that: The steps include: (1) Preparation of macromolecular long-branched grafting agent: a Preparation of 1,3-butadiene homopolymer (BR): In a polymerization kettle, argon gas is introduced for replacement, and solvent, 1,3-butadiene, structure regulator, and initiator 1 are added to the polymerization kettle in sequence, and the temperature is raised to react until no free monomer exists. The rubber solution is wet-coagulated and dried to obtain a BR homopolymer; b. Preparation of macromolecular long-chain branching grafting agent: inert gas is introduced into the reactor for replacement, solvent is added, the temperature is increased, and alkylaluminoxane co-catalyst is added under stirring, and stirring is continued under the protection of inert gas; then BR homopolymer and solution are mixed and stirred to dissolve, and after complete dissolution, they are added into the autoclave together with long-chain α-olefin and nickel-based complex catalyst, and ethylene is introduced at this time for reaction; after the reaction is completed, the macromolecular long-chain branching grafting agent is obtained by centrifugal separation and drying; (2) Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile rubber: a Preparation of hydrogenated nitrile rubber (HNBR): First, the nitrile rubber is dissolved in a chlorobenzene solution to prepare a rubber solution, and then the rubber solution is added to a reactor and an inert gas is introduced to remove the air in the reactor. Then, the inert gas in the reactor is removed with hydrogen, and then a xylene solution of Grubbs I catalyst is added under nitrogen protection, pressurized, heated, reacted, the system is cooled, condensed, and vacuum dried to obtain HNBR rubber; b. Preparation of deformation-resistant, low-temperature grade hydrogenated nitrile rubber: 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 macromolecular long-branched chain grafting agent is added to the reactor, stirred and mixed, heated, and a mixed solution of initiator 2 and chlorobenzene is added to react, flocculated with anhydrous ethanol, washed, and dried to obtain a deformation-resistant, low-temperature grade hydrogenated nitrile rubber; The macromolecular long-branched grafting agent has the following structure: Among them, BR is a 1,3-butadiene homopolymer segment, R is C6~C 12 m and n are the number of repeating units, n≥1, and m≥1; the number average molecular weight (Mn) of the macromolecular long chain grafting agent is 7000-9000.

2. The preparation method according to claim 1, characterized in that: The long-chain α-olefin is selected from one of 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene and 1-dodecene.

3. The preparation method according to claim 1, characterized in that: The nickel-based complex catalyst is selected from one of (1-naphthyl)〔8-(diphenylphosphino)quinoline〕nickel chloride, trans-phenyl(bis(triphenylphosphine))nickel bromide and 2,5-diformylpyrrole nickel dibromide.

4. The preparation method according to claim 1, characterized in that: The alkylaluminoxane cocatalyst is selected from one of methylaluminoxane (MAO) and ethylaluminoxane (EAO).

5. 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.

6. 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 0.01-0.1 parts based on 100 parts of the mass of the HNBR rubber.

7. 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%.

8. 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.

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

10. The preparation method according to claim 1, characterized in that: In step (1) a, the mass ratio of the solvent, 1,3-butadiene and structure regulator is 2-4:1:0.005-0.

01.

11. The preparation method according to claim 1, characterized in that: In step (1) b, the mass ratio of the solvent, alkylaluminoxane cocatalyst, BR homopolymer, solution, long-chain α-olefin, and nickel-based complex catalyst is 400-500:20-30:3.0-5.0:100-200:10-20:

1.

12. The preparation method according to claim 1, characterized in that: In step (2) a, based on 100 parts by mass of the nitrile rubber, the mass ratio of the nitrile rubber to the Grubbs I catalyst is 100:0.02-0.1; and the degree of hydrogenation HD of the HNBR rubber is less than 90%.

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

14. The preparation method according to claim 1, characterized in that: In step (2) b, the grafting rate of the deformation-resistant, low-temperature grade hydrogenated nitrile rubber is 2.9% to 3.7%.

15. A deformation-resistant, low-temperature grade hydrogenated nitrile rubber obtained by the preparation method according to any one of claims 1 to 14.

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