High-temperature super-oil-resistant nuclear power rubber expansion joint

Abstract

The invention belongs to the technical field of rubber expansion joints, and particularly relates to a high-temperature type super-oil-resistant nuclear power rubber expansion joint which comprises a rubber ball body, the rubber ball body comprises inner-layer rubber, outer-layer rubber, an inner reinforcing layer, an outer reinforcing layer and reinforcing layer coating rubber, the inner-layer rubber is composed of hydrogenated butadiene-acrylonitrile rubber, and the outer-layer rubber is composed of hydrogenated butadiene-acrylonitrile rubber. And the outer layer rubber is composed of hydrogenated nitrile rubber, chloroprene rubber, ethylene propylene diene monomer rubber or composite rubber thereof. The rubber expansion joint can effectively solve the problems that a traditional oil-resistant rubber expansion joint is low in temperature resistance grade; the rubber expansion joint solves the technical problems that an existing rubber expansion joint is poor in flexibility, poor in adaptability to oil media, poor in using performance in oil or corrosive media, poor in anti-aging performance, prone to deformation in the using process, short in service life and uncontrollable in quality, and flexibility and rigidity of a traditional rubber expansion joint are not considered at the same time.

Description

Technical Field

[0001] The present invention belongs to the technical field of rubber expansion joints, and particularly relates to a high-temperature and super oil-resistant nuclear power rubber expansion joint. Background Art

[0002] Rubber expansion joints have a large displacement compensation capacity, can compensate for axial, radial, and angular displacements, and have the capabilities of reducing noise, vibration, and corrosion. They have the characteristics of good elasticity, large displacement, good vibration absorption and noise reduction effects, and convenient installation, and are widely used in the pipeline systems of power, water supply and drainage, heating, ventilation and air conditioning, fire protection, papermaking, pharmaceutical, shipbuilding, chemical industry, etc.

[0003] When the emergency diesel engine in a nuclear power plant operates, a rubber expansion joint is required to absorb vibration and noise and compensate for the displacements in all directions generated by the system. Traditional rubber expansion joints have the following disadvantages: ① Due to the deviation errors caused by pipeline installation or operation, the fixed rubber expansion joint has installation accuracy errors and cannot be adjusted; ② There are various corrosive or pyrolytic media such as fuel oil (including biofuel oil), lubricating oil (added with various additives), and antifreeze (added with various additives) in the diesel engine system itself. Traditional oil-resistant rubbers cannot adapt to various medium components, have poor replaceability, short service life, and are limited in terms of use range and matching; ③ The operating temperature of traditional rubber expansion joints is relatively low (about 80 °C), and their performance drops significantly at high temperatures, and accidents often occur during use; ④ Traditional loose-type rubber expansion joints have a low pressure resistance level, and the rubber sphere is easily detached and deformed during use; ⑤ Traditional rubber expansion joints have poor corrosion resistance, poor anti-aging performance, poor use reliability, short service life, and there are risks that cannot be controlled, such as the expansion joints with low or high pressure resistance levels have too high rigidity and may suddenly burst (also known as explosion) during use, and the displacement compensation amount is small.

[0004] To solve the above problems, we have made improvements and introduced a high-temperature and super oil-resistant nuclear power rubber expansion joint. Summary of the Invention

[0005] The purpose of the present invention is to provide a high-temperature and super oil-resistant nuclear power rubber expansion joint, which can effectively solve the technical problems of traditional oil-resistant rubber expansion joints, such as low temperature resistance level, insufficient adaptability to oil media, degradation of performance in oil or corrosive media, poor anti-aging performance, deformation during use, short service life, uncontrollable quality, and failure to balance flexibility and rigidity of traditional rubber expansion joints.

[0006] Technical solutions for achieving the purpose of the present invention:

[0007] A high-temperature and super oil-resistant nuclear power rubber expansion joint, the rubber expansion joint includes a rubber sphere, and the rubber sphere includes: an inner rubber layer, an outer rubber layer, an inner reinforcement layer, an outer reinforcement layer, and a reinforcement layer coating rubber. The inner rubber layer is composed of a hydrogenated nitrile rubber compound, and the outer rubber layer is composed of a hydrogenated nitrile rubber compound or a chloroprene rubber compound or an ethylene propylene diene monomer rubber compound or a composite rubber compound thereof;

[0008] The hydrogenated nitrile rubber compound, by mass, contains: 100 parts of hydrogenated nitrile rubber, 15 - 95 parts of a reinforcing filler, 2 - 20 parts of a plasticizer or softener, 0.5 - 4.5 parts of an antioxidant, 0.5 - 8.0 parts of a vulcanizing agent, 0.4 - 6.0 parts of a co-crosslinking agent, 0.5 - 15.0 parts of an activator, 0.5 - 4.5 parts of an accelerator, and 0.5 - 3.5 parts of a processing aid.

[0009] In the hydrogenated nitrile rubber compound, the reinforcing filler is one or more of HAF high abrasion furnace black N330, FEF fast extrusion furnace black N550, or SRF-HMNS non-polluting high modulus semi-reinforcing furnace black; the plasticizer or softener is dibutyl diglycol adipate TP-95; the antioxidant is one or more of octylated diphenylamine ODPA, zinc 2-mercapto-5-methylbenzimidazole ZnMMBI, 2,2,4-trimethyl-1,2-dihydroquinoline RD, or 2-mercaptobenzimidazole MB; the vulcanizing agent is one or more of di-tert-butyl peroxide diisopropylbenzene BIBP, or dicumyl peroxide DCP, 1,1'-dithiobis(hexanecarboxamide) DTDC-80, sulfur granule S-80G; the crosslinking agent is one or two of triallyl isocyanurate TAIC, or N,N-m-phenylene bismaleimide HAV2; the activator is one or more of polyethylene wax AC617A, polyethylene glycol PEG4000, zinc oxide ZnO, or magnesium oxide MgO; the accelerator is tetramethylthiuram disulfide TMTD; the processing aid is one or more of a release agent, a tackifier, a demolding agent. The release agent is stearic acid, the tackifier is resin, and the demolding agent is silicone oil.

[0010] The chloroprene rubber compound, by mass, contains: 100 parts of chloroprene rubber; 3 - 5 parts of a vulcanizing agent; 1.5 - 6.0 parts of a processing aid; 0.5 - 3.0 parts of an antioxidant; 30 - 55 parts of a reinforcing filler; 5 - 25 parts of an abrasion-resistant filler; 5 - 25 parts of a plasticizer; 0.1 - 0.6 parts of a crosslinking agent.

[0011] In the chloroprene rubber compound, the reinforcing filler is one or more of FEF fast extrusion furnace black N550, HAF high abrasion furnace black N330, general purpose carbon black N660, or fumed or precipitated silica; the plasticizer is one or two of dibutyl phthalate DBP plasticizer, or dioctyl phthalate DOP plasticizer; the abrasion-resistant filler is barium sulfate Ba 2 SO4 , one or more of mica powder, talc powder, or hard kaolin; the vulcanizing agent is one or more of zinc oxide ZnO, lead oxide PbO, or lead tetraoxide Pb 3 O 4 in one or more of them; the crosslinking agent is ethylene thiourea NA-22; the processing aid is one or more of a releasing agent, an anti-scorching agent, or an acid absorbent. The releasing agent is stearic acid, the anti-scorching agent is magnesium oxide MgO, 2,2'-dithiobenzothiazole DM, and the acid absorbent is calcium oxide CaO; the anti-aging agent is one or more of N-1-phenylaniline antioxidant A, N-isopropyl-N'-phenyl-p-phenylenediamine antioxidant 4010NA, N-(1-methylisoamyl)-N`-phenyl-p-phenylenediamine antioxidant 4020, N,N'-bis(1,4-dimethylpentyl)-p-phenylenediamine antioxidant 4030, or chlorinated paraffin.

[0012] The ethylene propylene diene monomer (EPDM) rubber compound, by mass, contains: 95 to 65 parts of high Mooney viscosity EPDM rubber; 5 to 35 parts of low Mooney viscosity EPDM rubber or oil-extended EPDM rubber; 3 to 8 parts of activator; 1.0 to 10 parts of processing aid; 1 to 3 parts of anti-aging agent; 10 to 80 parts of filler; 5 to 25 parts of plasticizer or softener; 1.5 to 7.0 parts of vulcanizing agent; 1.0 to 4.5 parts of crosslinking agent.

[0013] In the EPDM rubber compound, the filler is one or more of FEF fast extrusion furnace black N550, HAF high abrasion furnace black N330, general carbon black N660, fumed or precipitated silica, or kaolin; the plasticizer or softener is one or more of paraffin oil, naphthenic oil, microcrystalline wax, transformer oil, low-grade engine oil, or triisooctyl phosphite TOTM; the vulcanizing agent is one or more of dicumyl peroxide DCP, bis(tert-butylperoxyisopropyl)benzene BIBP, or sulfur granule S-80G; the crosslinking agent is one or more of triallyl isocyanurate TAIC, triallyl cyanurate TAC, or N,N-m-phenylene bismaleimide HAV2; the processing aid is one or two of a releasing agent or a tackifier; the releasing agent is stearic acid, and the tackifier is alkylphenol formaldehyde resin SP1077, coumarone resin, rosin; the anti-aging agent is one or more of N-1-phenylaniline antioxidant A, 2,2,4-trimethyl-1,2-dihydroquinoline RD, or 2-mercaptobenzimidazole MB, or chlorinated paraffin; the activator is one or more of zinc oxide ZnO or lead oxide PbO.

[0014] The material of the inner reinforcing layer and the outer reinforcing layer is aramid cord, nylon cord, steel cord or their composite materials.

[0015] The rubber expansion joint further includes a fixing ring and a size positioning ring. The fixing ring is fixedly connected to both sides of the rubber sphere. One side of the fixing ring is a circular arc flange, and the other side is a clamping groove with a groove. The size positioning ring matches the groove of the fixing ring, and the size positioning ring is embedded in the groove of the fixing ring. Both ends of the rubber sphere are flipped 90° and extended to the size positioning ring embedded in the groove of the fixing ring to form a flanged rubber.

[0016] The inner reinforcing layer and the outer reinforcing layer are arranged between the inner rubber layer and the outer rubber layer. The first inner reinforcing layer, the second inner reinforcing layer, and the outer reinforcing layer are arranged in sequence from inside to outside. There is a reinforcing layer coating rubber between the first inner reinforcing layer and the second inner reinforcing layer, and there is a reinforcing layer coating rubber between the second inner reinforcing layer and the outer reinforcing layer.

[0017] The inner rubber layer, the outer rubber layer, the inner reinforcing layer, the outer reinforcing layer, and the reinforcing layer coating rubber are integrally formed by integral vulcanization; the flanged rubber and the size positioning ring are integrally bonded by vulcanization to ensure that during the flexible deformation process of the rubber body, the rigid support of the size positioning ring ensures that the orifice size does not change during the use of the expansion joint.

[0018] The beneficial technical effects of the present invention are as follows:

[0019] 1. A high-temperature and super oil-resistant nuclear power rubber expansion joint provided by the present invention, by selecting high-performance hydrogenated nitrile rubber as the raw material, and obtaining a hydrogenated nitrile rubber sheet with excellent comprehensive performance through formula optimization, making it have excellent temperature resistance, oil resistance (good corrosion resistance, wear resistance, and anti-aging performance for various corrosive media (especially oil media)), and can be used as the inner and outer rubber layers of the high-temperature and super oil-resistant nuclear power rubber expansion joint to ensure its long service life and use reliability.

[0020] 2. A high-temperature and super oil-resistant nuclear power rubber expansion joint provided by the present invention, by using an aramid cord or flexible steel cord reinforcement structure, and utilizing the high strength and high flexibility of the aramid cord and flexible steel cord, solves the disadvantages of the traditional rubber expansion joint with low compressive strength grade of rigid steel polyester cord, excessive flexibility resulting in large deformation, low vacuum resistance, and high compressive strength grade of rigid steel, large stiffness, and small compensation.

[0021] 3. A high-temperature and super oil-resistant nuclear power rubber expansion joint provided by the present invention, by setting a size positioning ring structure, to prevent deformation and accidental detachment during use, and ensure safety and reliability during use. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic structural diagram of a high-temperature and super oil-resistant nuclear power rubber expansion joint provided by the present invention;

[0023] Figure 2 For Figure 1Enlarged view of the middle region A. Detailed implementation mode

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0025] As Figure 1 Shown in the figure, a high-temperature and super oil-resistant nuclear power rubber expansion joint provided by the present invention includes: a rubber sphere, fixed rings or flanges on both sides of the rubber sphere, and a size positioning ring. The rubber sphere includes: an inner rubber layer, an outer rubber layer, an inner reinforcing layer, an outer reinforcing layer, and a reinforcing layer coating rubber; the fixed ring or flange is composed of a clamping groove with a circular arc flange on one side and a groove on the other side; the size positioning ring is an embedded metal ring matching the size of the fixed ring groove, and can be in the shape of a metal circle, sheet, etc.; the inner rubber layer and the outer rubber layer are formed by winding and laminating multiple rubber plates. Between the inner and outer rubber layers, there are wrapped inner and outer reinforcing layers (such as aramid, nylon, and steel cord) and a reinforcing layer coating rubber. The reinforcing layer is formed by winding in a positive and negative alternating manner to form a grid-shaped compressive strengthening layer. The inner and outer rubber layers and the reinforcing layer extend to the size positioning ring embedded in the fixed ring groove according to the positioning and are flipped 90° to form a flange sealing surface. Between the inner rubber plates, between the reinforcing layer and the reinforcing layer coating rubber, and between the outer rubber plates, they are integrally formed by vulcanization. The flanged rubber and the size positioning ring are bonded into a whole by vulcanization to ensure that during the flexible deformation process of the rubber body, the rigid support of the size positioning ring (metal) is used to ensure that the orifice size does not change during the use of the expansion joint.

[0026] The inner rubber layer is composed of hydrogenated nitrile rubber (HNBR) compound. Hydrogenated nitrile rubber (HNBR) is a high-saturation, high-temperature-resistant, and super oil-resistant special synthetic rubber in which the double bonds on the polybutadiene chain segments in the molecular chain of nitrile rubber (NBR) are saturated through hydrogenation. Hydrogenated nitrile rubber (HNBR) has high physical and mechanical properties at normal temperature or high temperature, and comprehensive properties such as heat resistance, heat and oil aging resistance, acid gasoline resistance, wear resistance, ozone resistance, and relatively excellent low-temperature performance.

[0027] The outer layer of rubber is composed of hydrogenated nitrile butadiene rubber (HNBR) compound, chloroprene rubber (CR) compound, ethylene propylene diene monomer (EPDM) rubber compound or their composite rubber. The hydrogenated nitrile butadiene rubber (HNBR) compound is as described above; Chloroprene rubber (CR) is an elastomer formed by the α-polymerization of chloroprene (i.e., 2-chloro-1,3-butadiene) as the main raw material, with good mechanical properties of the material, resistance to oil, heat, fire, sunlight, ozone, acids and alkalis, chemical media, and excellent flex fatigue performance; Ethylene propylene diene monomer (EPDM) rubber is a terpolymer of ethylene, propylene and non-conjugated diene. Its main polymer chain is completely saturated, belonging to a highly saturated special synthetic rubber, with superior oxidation resistance, ozone resistance and corrosion resistance, and good resistance to hot water and steam; The binary or multi-component composite materials composed of hydrogenated nitrile butadiene rubber (HNBR), chloroprene rubber (CR) or ethylene propylene diene monomer (EPDM) rubber can take into account the optimal comprehensive performance of various materials used alone.

[0028] The reinforcing layer is made of aramid cord fabric, nylon cord fabric, steel cord or their composite materials; The coating rubber of the reinforcing layer is rubber matching with the inner and outer layer rubbers.

[0029] The parts by mass of the raw materials involved in the following examples are all parts by mass.

[0030] Example 1: Hydrogenated nitrile butadiene rubber HNBR compound formula 1

[0031] 100 parts of hydrogenated nitrile butadiene rubber HNBR; 2 - 8 parts of zinc oxide ZnO; 1 - 5 parts of magnesium oxide MgO; 0.5 - 2.5 parts of stearic acid; 0.5 - 1.5 parts of antioxidant ODPA (octylated diphenylamine); 0.2 - 0.8 parts of antioxidant ZnMMBI (zinc salt of 2-mercapto-5-methylbenzimidazole); 15 - 35 parts of carbon black N330 (HAF high abrasion furnace black); 10 - 45 parts of carbon black N550 (FEF fast extrusion furnace black); 2 - 12 parts of TP95 plasticizer (dibutyl diglycol adipate); 4 - 10 parts of vulcanizing agent BIBP (di-tert-butyl peroxide diisopropylbenzene); 1.5 - 6.5 parts of crosslinking agent TAIC (triallyl isocyanurate).

[0032] Example 2: Hydrogenated nitrile butadiene rubber HNBR compound formula 2

[0033] 100 parts of hydrogenated nitrile rubber HNBR; 2 - 8 parts of zinc oxide ZnO; 1 - 5 parts of magnesium oxide MgO; 0.5 - 2.5 parts of stearic acid; 0.5 - 1.5 parts of antioxidant RD (2,2,4 - trimethyl - 1,2 - dihydroquinoline); 0.5 - 1.5 parts of antioxidant MB (2 - mercaptobenzimidazole); 10 - 30 parts of carbon black N330 (HAF high abrasion furnace black); 15 - 50 parts of carbon black N774 (SRF - HMNS non - polluting high modulus semi - reinforcing furnace black); 3 - 10 parts of TP95 plasticizer (dibutyl diglycol adipate); 2.5 - 7.0 parts of vulcanizing agent DCP (dicumyl peroxide); 1.0 - 5.0 parts of cross - linker HAV2 (N,N - m - phenylene bismaleimide).

[0034] Example 3: HNBR rubber compound formulation 3

[0035] 100 parts of hydrogenated nitrile rubber HNBR; 3 - 10 parts of zinc oxide ZnO; 1 - 3 parts of magnesium oxide MgO; 0.5 - 2.0 parts of stearic acid; 0.5 - 1.5 parts of antioxidant RD (2,2,4 - trimethyl - 1,2 - dihydroquinoline); 0.5 - 1.5 parts of antioxidant MB (2 - mercaptobenzimidazole); 25 - 60 parts of carbon black N550 (FEF fast extrusion furnace black); 2 - 15 parts of TP95 plasticizer (dibutyl diglycol adipate); 1.0 - 5.0 parts of accelerator TMTD (tetramethylthiuram disulfide); 1.0 - 3.0 parts of vulcanizing agent DTDC - 80 (1,1’ - dithiobis - caprolactam).

[0036] Example 4: HNBR rubber compound formulation 4

[0037] 100 parts of hydrogenated nitrile rubber HNBR; 3 - 5 parts of zinc oxide ZnO; 0.5 - 1.5 parts of antioxidant RD (2,2,4 - trimethyl - 1,2 - dihydroquinoline); 0.5 - 1.5 parts of antioxidant MB (2 - mercaptobenzimidazole); 10 - 30 parts of carbon black N330 (HAF high abrasion furnace black); 20 - 40 parts of carbon black N550 (FEF fast extrusion furnace black); 5 - 20 parts of carbon black N774 (SRF - HMNS non - polluting high modulus semi - reinforcing furnace black); 5 - 10 parts of TP95 plasticizer (dibutyl diglycol adipate); 0.5 - 3.0 parts of surfactant PEG4000 (polyethylene glycol); 0.5 - 2.5 parts of activator AC617A (polyethylene wax); 3.0 - 8.0 parts of vulcanizing agent DCP (dicumyl peroxide); 1.0 - 4.5 parts of cross - linker TAIC (triallyl isocyanurate); 0.2 - 1.8 parts of vulcanizing agent S - 80G

[0038] Example 5: CR rubber compound formulation

[0039] 100 parts of chloroprene rubber CR; 3 - 5 parts of zinc oxide ZnO; 2 - 4 parts of light or active magnesium oxide MgO; 0.5 - 1.5 parts of stearic acid; 0.5 - 1.5 parts of antioxidant A (N - 1 - phenylaniline); 0.5 - 1.5 parts of antioxidant 4010NA (N - isopropyl - N’ - phenyl - p - phenylenediamine); 30 - 55 parts of carbon black N550 (FEF fast extrusion furnace black); 5 - 25 parts of barium sulfate Ba2SO4; 5 - 25 parts of DBP plasticizer (dibutyl phthalate); 0.1 - 0.6 parts of accelerator NA - 22 (ethylene thiourea).

[0040] Example 6: Formula of ethylene - propylene - diene monomer (EPDM) rubber compound

[0041] 95 - 65 parts of ethylene - propylene - diene monomer (EPDM) (high Mooney); 5 - 35 parts of ethylene - propylene - diene monomer (EPDM) (low Mooney or oil - extended); 3 - 8 parts of zinc oxide ZnO; 1.0 - 2.0 parts of stearic acid; 1 - 3 parts of antioxidant A (N - 1 - phenylaniline); 2 - 8 parts of tackifying resin SP1077 (alkylphenolic resin); 25 - 50 parts of carbon black N550 (FEF fast extrusion furnace black); 10 - 30 parts of carbon black N660 (GPF general purpose furnace black); 10 - 40 parts of clay; 5 - 25 parts of paraffin oil; 1.5 - 5.0 parts of vulcanizing agent DCP (dicumyl peroxide); 1.0 - 4.5 parts of cross - linker TAIC (triallyl isocyanurate); 0.2 - 1.8 parts of sulfur granule S - 80G.

[0042] Example 7: Formula of composite rubber compound of hydrogenated nitrile - butadiene rubber (HNBR) and chloroprene rubber (CR)

[0043] 65 - 95 parts of hydrogenated nitrile - butadiene rubber HNBR; 35 - 5 parts of chloroprene rubber CR; 2 - 8 parts of zinc oxide ZnO; 0.2 - 1.50 parts of magnesium oxide MgO; 0.5 - 2.0 parts of stearic acid; 0.3 - 1.2 parts of antioxidant RD (2,2,4 - trimethyl - 1,2 - dihydroquinoline); 0.3 - 1.2 parts of antioxidant MB (2 - mercaptobenzimidazole); 0.1 - 0.8 parts of antioxidant A (N - 1 - phenylaniline); 0.2 - 0.6 parts of antioxidant 4010NA (N - isopropyl - N’ - phenyl - p - phenylenediamine); 15 - 35 parts of carbon black N330 (HAF high abrasion furnace black); 10 - 45 parts of carbon black N550 (FEF fast extrusion furnace black); 2 - 10 parts of barium sulfate Ba2SO4; 1.5 - 11.5 parts of TP95 plasticizer (dibutyl diglycol adipate); 2.5 - 9.0 parts of vulcanizing agent BIBP (di - tert - butyl peroxide - dicumyl peroxide); 1.0 - 5.5 parts of cross - linker TAIC (triallyl isocyanurate); 0.05 - 0.4 parts of accelerator NA - 22 (ethylene thiourea).

[0044] Example 8: For other cases, such as the composites of hydrogenated nitrile rubber (HNBR) and ethylene propylene diene monomer rubber (EPDM), hydrogenated nitrile rubber (HNBR) and ethylene propylene diene monomer rubber (EPDM) and chloroprene rubber (CR), ethylene propylene diene monomer rubber (EPDM) and chloroprene rubber (CR), hydrogenated nitrile rubber (HNBR) and acrylate rubber (ACM), hydrogenated nitrile rubber (HNBR) and chlorosulfonated polyethylene rubber (CSM), as well as their binary and multi-component composite formulations, no further examples will be given one by one.

[0045] Example 9: An example of the manufacturing process of rubber sheets is as follows:

[0046] Batching --- Plasticizing raw rubber alone --- Parking --- Plasticizing the mixed raw rubber --- Adding compounding agent 1 (such as dispersant, 1 / 2 reinforcing filler, compatibilizing filler, tackifying resin, antioxidant) --- Adding compounding agent 2 (such as activator, lubricant, 2 / 3 reinforcing filler, plasticizer) --- Parking and cooling --- Adding vulcanizing agent, vulcanization accelerator, crosslinking agent, crosslinking assistant --- Thin passing on an open mill --- Making a triangle package --- Extruding a sheet --- Parking and cooling --- Feeding a cold feed extruder --- Extruding a duckbill-shaped rubber sheet --- Calendering on a calender --- Cooling --- Rewinding --- Rubber sheet.

[0047] Example 10: The relevant performance verification of a high-temperature resistant and ultra oil-resistant nuclear power rubber expansion joint of the present invention is as follows:

[0048] 1. Performance comparison:

[0049] The hydrogenated nitrile rubber (HNBR) mentioned below is the hydrogenated nitrile rubber (HNBR) of the formulation of the present invention.

[0050] Physical and mechanical properties: The tensile strength of hydrogenated nitrile rubber (HNBR) can reach below 20 MPa, and the elongation at break can reach above 450%; while the conventional physical and mechanical properties of traditional nitrile rubber (NBR): the tensile strength is only below 12 MPa, and the elongation at break can reach above 380%.

[0051] Heat aging resistance: The performance change rate of the hot air aging performance (150 °C * 72 h) of hydrogenated nitrile rubber (HNBR) ≤ 15%; while the performance change rate of the hot air aging performance (100 °C * 48 h) of nitrile rubber (NBR) reaches 30%; under the test conditions of the same 100 °C * 72 h and 25% compression, the compression set rate of hydrogenated nitrile rubber (HNBR) ≤ 20%, while the compression set rate of nitrile rubber (NBR) ≤ 45%.

[0052] 1). 0# diesel test

[0053] Soak at room temperature for 168 h, the mass change rate of hydrogenated nitrile rubber HNBR ≤ 3%, and the performance change rate ≤ 5%; the mass change rate of nitrile rubber NBR ≤ 3%, and the performance change rate ≥ 35%; soak at 100 °C for 168 h, the mass change rate of hydrogenated nitrile rubber HNBR ≤ 3%, and the performance change rate ≤ 8%; the mass change rate of nitrile rubber NBR ≤ 12%, and the performance change rate ≥ 50%; soak at room temperature for 1 year, the mass change rate of hydrogenated nitrile rubber HNBR ≤ 5%, and the performance change rate ≤ 12%; the mass change rate of nitrile rubber NBR ≤ 24%, and the performance change rate ≥ 65%.

[0054] 2) Diesel engine lubricating oil (5W - 40) test

[0055] Soak at room temperature for 168 h, the mass change rate of hydrogenated nitrile rubber HNBR ≤ 2%, and the performance change rate ≤ 8%; the mass change rate of nitrile rubber NBR ≤ 6%, and the performance change rate ≥ 35%; soak at 100 °C for 168 h, the mass change rate of hydrogenated nitrile rubber HNBR ≤ 3%, and the performance change rate ≤ 12%; the mass change rate of nitrile rubber NBR ≤ 18%, and the performance change rate ≥ 60%; soak at room temperature for 1 year, the mass change rate of hydrogenated nitrile rubber HNBR ≤ 6%, and the performance change rate ≤ 15%; the mass change rate of nitrile rubber NBR ≤ 30%, and the performance change rate ≥ 75%.

[0056] 3) Antifreeze test

[0057] Soak at room temperature for 168 h, the mass change rate of hydrogenated nitrile rubber HNBR ≤ 2.8%, and the performance change rate ≤ 4%; the mass change rate of nitrile rubber NBR ≤ 4.9%, and the performance change rate ≥ 24%; soak at 100 °C for 168 h, the mass change rate of hydrogenated nitrile rubber HNBR ≤ 3.6%, and the performance change rate ≤ 9%; the mass change rate of nitrile rubber NBR ≤ 15%, and the performance change rate ≥ 32%; soak at room temperature for 1 year, the mass change rate of hydrogenated nitrile rubber HNBR ≤ 5.5%, and the performance change rate ≤ 16%; the mass change rate of nitrile rubber NBR ≤ 21%, and the performance change rate ≥ 48%.

[0058] 4) Static ozone test

[0059] Ozone concentration 50 ppm, test temperature 40 °C, elongation rate 40%, no crack was found on hydrogenated nitrile rubber HNBR after 1000 h test; while visible cracks occurred on nitrile rubber NBR after 385 h test.

[0060] 5) Dynamic ozone test

[0061] Ozone concentration is 50 ppm, test temperature is 40 °C, elongation at break is 40%, tensile frequency is 30 times / min. After 500 h of testing, no cracks were observed on hydrogenated nitrile rubber (HNBR); while visible cracks occurred on nitrile rubber (NBR) after 248 h of testing.

[0062] 6) Tensile fatigue performance test

[0063] Test strain value is 100%, test frequency is 300 r / min, number of tensile fatigue cycles is 500,000 times. The deformation rate of hydrogenated nitrile rubber (HNBR) is ≤0.5%, and no cracks are visible on the surface; while the deformation rate of nitrile rubber (NBR) is ≤8%, and surface cracks are visible at 120,000 times. At the end of the 500,000 - time test, no fracture occurred, but crack expansion was visible under a 30 - fold magnifying glass.

[0064] 2. Test verification effect of high - temperature and super - oil - resistant nuclear power rubber expansion joint

[0065] The aramid - reinforced high - temperature and super - oil - resistant nuclear power rubber expansion joint of the present invention was subjected to a hydrostatic strength test with a test pressure of 1.5 MPa and a pressure - holding time of 30 min; a vacuum tightness test with a test vacuum pressure of - 0.07 MPa and a pressure - holding time of 30 min; a water hammer pulse impact test with a maximum pressure grade of 3.8 MPa, a pulse frequency greater than 60 times / hour, and a pulse number of 5000 times; a fatigue motion test with a maximum lateral displacement of 30 mm, a test temperature of 110 °C, a test pressure of 1.5 MPa, a motion frequency not less than 1 Hz, and a cycle number of 200,000 times; a thermal aging test (simulating working conditions) with maximum lateral, axial, and angular displacements, a test temperature of 110 °C, a test pressure of 1.5 MPa, and a test time of 1000 hours; a seismic test with a maximum lateral displacement of 30 mm, a test pressure of 1.5 MPa, at 1 Hz / 10 times, 2 Hz / 40 times, 5 Hz / 50 times, 8 Hz / 1000 times; a pressure resistance test with a test pressure of 1.0 MPa and a pressure - holding time of 48 h, a test pressure of 2.0 MPa and a pressure - holding time of 24 h, and a burst test with a pressure greater than 4.0 MPa. After the above - mentioned sequential superimposed tests, no breakage, cracks, surface abnormal deformation, or damage were observed on the high - temperature and super - oil - resistant nuclear power rubber expansion joint of the present invention, and no leakage or seepage was observed in the seal.

[0066] 3. Application verification effect of high - temperature and super - oil - resistant nuclear power rubber expansion joint

[0067] For on - site verification, the aramid - reinforced high - temperature and super - oil - resistant nuclear power rubber expansion joint of the present invention was used in the media of 0# diesel and lubricating oil, with a use pressure of 0.6 MPa - 0.9 MPa, a use temperature of 65 °C - 95 °C, and an application time of 18 months. No leakage or damage was observed during the test process. After removal, upon inspection, the inner - layer rubber of the expansion joint was as smooth as new, and no obvious corrosion marks were found. No breakage or leakage was observed in the hydrostatic test with a test pressure of 1.5 MPa and a pressure - holding time of 24 h.

[0068] 4. Service life prediction

[0069] Laboratory test calculation: The service life of nitrile rubber NBR at room temperature (25°C) is only 9.5 years; while after the hot air accelerated aging test of hydrogenated nitrile rubber HNBR at a test temperature of 135°C for 106 days, the change rate of test performance is ≤35%. From this, it is estimated that the service life under the use condition of 80°C is 10 years. From this, it is judged that the service life of hydrogenated nitrile rubber HNBR at high temperature is far better than that of nitrile rubber NBR.

[0070] 5. Compressive capacity

[0071] For the high-temperature super oil-resistant nuclear power hydrogenated nitrile rubber expansion joint reinforced with aramid, the perimeter change rate is ≤4% under the use pressure of 1.0 MPa, while for the traditional nitrile rubber expansion joint reinforced with polyester, the perimeter change rate is at least ≥18% under the test pressure of 1.0 MPa; the burst pressure after the superimposed test of the high-temperature super oil-resistant nuclear power hydrogenated nitrile rubber expansion joint reinforced with aramid is greater than 4.0 MPa, which is more than 4 times the design pressure, while the individual burst pressure of the traditional nitrile rubber expansion joint reinforced with polyester is less than 2.8 MPa, not reaching 3 times the design pressure. From this, it is judged that the compressive capacity of the high-temperature super oil-resistant nuclear power hydrogenated nitrile rubber expansion joint reinforced with aramid is far better than that of the traditional nitrile rubber expansion joint reinforced with polyester.

[0072] 6. Anti-detachment and anti-deformation capacity

[0073] After 1000 hours of heat aging test, the dimensions of the high-temperature super oil-resistant nuclear power hydrogenated nitrile rubber expansion joint with an increased size positioning ring basically do not change. Even under the water hammer impact test pressure of up to 3.8 MPa, the dimensions do not change, and no seal leakage or seepage is observed during the test; while after 1000 hours of heat aging test, the orifice size of the traditional loose sleeve rubber expansion joint shrinks severely, with a deformation rate of 32% (flexible reinforcement) and 19% (rigid reinforcement), and the sealing surface is inclined and deformed, with a deformation rate of 18% (flexible reinforcement) and 10% (rigid reinforcement). During the test, the bolt tightening torque is 20 - 40% higher than that of the high-temperature super oil-resistant nuclear power hydrogenated nitrile rubber expansion joint with an increased size positioning ring. Due to the rigid fixed connection of the card slot, there is no risk of the rubber sphere falling off due to any impact for the high-temperature super oil-resistant nuclear power hydrogenated nitrile rubber expansion joint with an increased size positioning ring.

[0074] 7. Impact resistance

[0075] The aramid-reinforced high-temperature and super oil-resistant nuclear power hydrogenated nitrile rubber expansion joint has withstood 5,000 times of water hammer pulse impacts with a maximum test pressure of 3.8 MPa and a pulse frequency of not less than 60 times per hour, and 200,000 times of dynamic fatigue tests with a maximum lateral displacement of 30 mm, a test pressure of 1.5 MPa, and a cyclic motion frequency of not less than 1 Hz, without any abnormal deformation, no groove, no damage, and no leakage. For the conventional nitrile rubber expansion joint, a break or explosion occurred after only 689 times of water hammer impacts. For the traditional rubber expansion joint reinforced with rigid steel wires, a break and explosion occurred after 2,082 times of water hammer impacts, and there was a relatively serious large-area delamination and peeling between the rigid reinforcing steel wires and the inner and outer rubber layers at the break, further expanding the break. Therefore, the aramid-reinforced high-temperature and super oil-resistant nuclear power hydrogenated nitrile rubber expansion joint has a great advantage in resisting water hammer impacts.

[0076] The present invention has been described in detail above in conjunction with the accompanying drawings and embodiments. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those of ordinary skill in the art, various changes can be made without departing from the gist of the present invention. The content not described in detail in the present invention can all adopt the prior art.

Claims

1. A high-temperature and super oil-resistant nuclear power rubber expansion joint, characterized in that, the rubber expansion joint comprises a rubber sphere, and the rubber sphere includes: an inner rubber layer, an outer rubber layer, an inner reinforcing layer, an outer reinforcing layer, and a reinforcing layer coating rubber. The inner rubber layer is composed of a hydrogenated nitrile rubber compound, and the outer rubber layer is composed of a hydrogenated nitrile rubber compound or a chloroprene rubber compound or an ethylene propylene diene monomer rubber compound or a composite rubber compound thereof; The hydrogenated nitrile rubber compound, by mass parts, comprises: 100 parts of hydrogenated nitrile rubber, 15-95 parts of a reinforcing filler, 2-20 parts of a plasticizer or softener, 0.5-4.5 parts of an antioxidant, 0.5-8.0 parts of a vulcanizing agent, 0.4-6.0 parts of a co-crosslinking agent, 0.5-15.0 parts of an activator, 0.5-4.5 parts of an accelerator, and 0.5-3.5 parts of a processing aid.

2. The high-temperature and super oil-resistant nuclear power rubber expansion joint according to claim 1, characterized in that, in the hydrogenated nitrile rubber compound, the reinforcing filler is one or more of HAF high abrasion furnace black N330, FEF fast extrusion furnace black N550, or SRF-HMNS non-polluting high modulus semi-reinforcing furnace black; the plasticizer or softener is dibutyl diglycol adipate TP-95; the antioxidant is one or more of octylated diphenylamine ODPA, zinc 2-mercapto-5-methylbenzimidazole ZnMMBI, 2,2,4-trimethyl-1,2-dihydroquinoline RD, or 2-mercaptobenzimidazole MB; the vulcanizing agent is one or more of di-tert-butyl peroxide diisopropylbenzene BIBP, or dicumyl peroxide DCP, 1,1'-dithiobis(hexanamide) DTDC-80, sulfur granule S-80G; the crosslinking agent is one or two of triallyl isocyanurate TAIC, or N,N-m-phenylene bismaleimide HAV2; the activator is one or more of polyethylene wax AC617A, polyethylene glycol PEG4000, zinc oxide ZnO, or magnesium oxide MgO; the accelerator is tetramethylthiuram disulfide TMTD; the processing aid is one or more of a separating agent, a tackifier, and a demolding agent. The separating agent is stearic acid, the tackifier is resin, and the demolding agent is silicone oil.

3. The high-temperature and super oil-resistant nuclear power rubber expansion joint according to claim 1, characterized in that, the chloroprene rubber compound, by mass parts, comprises: 100 parts of chloroprene rubber; 3-5 parts of a vulcanizing agent; 1.5-6.0 parts of a processing aid; 0.5-3.0 parts of an antioxidant; 30-55 parts of a reinforcing filler; 5-25 parts of an abrasion-resistant filler; 5-25 parts of a plasticizer; 0.1-0.6 parts of a crosslinking agent.

4. The high-temperature and super oil-resistant nuclear power rubber expansion joint according to claim 3, characterized in that, In the chloroprene rubber compound, the reinforcing filler is one or more of FEF fast extrusion furnace black N550, HAF high abrasion furnace black N330, general carbon black N660, or fumed or precipitated silica; the plasticizer is one or two of dibutyl phthalate DBP plasticizer or dioctyl phthalate DOP plasticizer; the wear-resistant filler is barium sulfate Ba 2 SO 4 , mica powder, talc powder, or one or more of hard kaolin; the vulcanizing agent is one or more of zinc oxide ZnO, lead oxide PbO, or lead tetroxide Pb 3 O 4 ; the crosslinking agent is ethylene thiourea NA-22; the processing and operation aids are one or more of a release agent, an anti-scorching agent, or an acid absorbent. The release agent is stearic acid, the anti-scorching agent is magnesium oxide MgO, 2,2'-dithiobenzothiazole DM, and the acid absorbent is calcium oxide CaO; the anti-aging agent is one or more of N-1-phenylaniline antioxidant A, N-isopropyl-N'-phenyl-p-phenylenediamine antioxidant 4010NA, N-(1-methylisoamyl)-N`-phenyl-p-phenylenediamine antioxidant 4020, N,N'-bis(1,4-dimethylpentyl)-p-phenylenediamine antioxidant 4030, or chlorinated paraffin.

5. The high-temperature and super oil-resistant nuclear power rubber expansion joint according to claim 1, characterized in that, The ethylene propylene diene monomer (EPDM) rubber compound, by mass parts, comprises: 95 - 65 parts of high Mooney viscosity EPDM rubber; 5 - 35 parts of low Mooney viscosity EPDM rubber or oil-extended EPDM rubber; 3 - 8 parts of activator; 1.0 - 10 parts of processing aid; 1 - 3 parts of anti-ager; 10 - 80 parts of filler; 5 - 25 parts of plasticizer or softener; 1.5 - 7.0 parts of vulcanizing agent; 1.0 - 4.5 parts of crosslinking agent.

6. A high-temperature super oil-resistant nuclear power rubber expansion joint according to claim 5, characterized in that in the EPDM rubber compound, the filler is one or more of FEF fast extrusion furnace black N550, HAF high abrasion furnace black N330, general carbon black N660, fumed or precipitated silica, or clay; the plasticizer or softener is one or more of paraffin oil, naphthenic oil, microcrystalline wax, transformer oil, low-grade engine oil, or triisooctyl phosphite TOTM; the vulcanizing agent is one or more of dicumyl peroxide DCP, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane BIBP, or sulfur granule S-80G; the crosslinking agent is one or more of triallyl isocyanurate TAIC, triallyl cyanurate TAC, or N,N-m-phenylene bismaleimide HAV2; the processing aid is one or two of a releasing agent or a tackifier; the releasing agent is stearic acid, and the tackifier is alkylphenol formaldehyde resin SP1077, coumarone resin, or rosin; the anti-ager is one or more of N-phenyl-1-naphthylamine antioxidant A, 2,2,4-trimethyl-1,2-dihydroquinoline RD, or 2-mercaptobenzimidazole MB, or chlorinated paraffin; the activator is one or more of zinc oxide ZnO or lead oxide PbO.

7. A high-temperature super oil-resistant nuclear power rubber expansion joint according to claim 1, characterized in that the materials of the inner reinforcing layer and the outer reinforcing layer are aramid cord, nylon cord, steel cord or their composite materials.

8. A high-temperature super oil-resistant nuclear power rubber expansion joint according to claim 1, characterized in that the rubber expansion joint further comprises a fixing ring and a size positioning ring. The fixing ring is fixedly connected to both sides of the rubber sphere. One side of the fixing ring is a groove with an arc flange, and the other side is a groove. The size positioning ring matches the groove of the fixing ring, and the size positioning ring is embedded in the groove of the fixing ring. The two ends of the rubber sphere are turned 90° and extended to the size positioning ring embedded in the groove of the fixing ring to form a flanged rubber.

9. A high-temperature super oil-resistant nuclear power rubber expansion joint according to claim 8, characterized in that the inner reinforcing layer and the outer reinforcing layer are arranged between the inner rubber and the outer rubber. The first inner reinforcing layer, the second inner reinforcing layer, and the outer reinforcing layer are arranged in sequence from the inside to the outside. There is a reinforcing layer coating rubber between the first inner reinforcing layer and the second inner reinforcing layer, and there is a reinforcing layer coating rubber between the second inner reinforcing layer and the outer reinforcing layer.

10. A high-temperature super oil-resistant nuclear power rubber expansion joint according to claim 9, characterized in that The inner rubber layer, outer rubber layer, inner reinforcing layer, outer reinforcing layer, and reinforcing layer coating rubber are integrally formed by integral vulcanization; the flanging rubber and the size positioning ring are integrally bonded by vulcanization to ensure that during the flexible deformation process of the rubber body, the rigid support of the size positioning ring ensures that the orifice size does not change during the use of the expansion joint.

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