A rubber ring for sealing a piston of a pump truck and a method for manufacturing the same

Abstract

The application relates to a rubber ring for sealing a pump truck piston and a preparation method thereof, and belongs to the technical field of rubber sealing rings. The rubber ring is divided into an inner ring and an outer ring, the outer ring wraps the inner ring, and the preparation raw materials of the outer ring include 62-75 parts of polyurethane particles, 5-10 parts of natural rubber, 2-5 parts of coumarone-indene resin, 7-9 parts of naphthenic oil and 4-12 parts of graphite; the preparation raw materials of the inner ring include 86-95 parts of polyurethane particles, 1-3 parts of tetrafluoroethylene powder and 5-10 parts of elastic microspheres. The rubber ring prepared by adopting the double-layer functional partition design of the outer ring wrapping the inner ring has good support and high-elasticity sealing performance. The inner ring adopts polyurethane+ tetrafluoroethylene powder+ elastic microspheres as a core support layer, relies on the high strength and high tear resistance of polyurethane itself; the outer ring adopts polyurethane+ natural rubber+ graphite-naphthenic oil paste+ coumarone-indene resin as a functional action layer, can be closely attached to a sealing surface and reduce gaps.

Description

Technical Field

[0001] This invention belongs to the field of rubber sealing ring technology, specifically relating to a rubber ring for sealing pump truck pistons and its preparation method. Background Technology

[0002] Rubber seals are ring-shaped sealing devices composed of one or more parts. They are usually fixed on the collars or gaskets of mechanical parts and prevent lubricating oil leakage and foreign matter intrusion through contact or gap structures. They are widely used in automotive, machinery, electronics and pipeline engineering and other fields.

[0003] However, some mechanical devices require the use of pistons. If the sealing ring is used in the piston, the repeated operation of the piston during use will cause heat to accumulate inside. The heat is transferred to the sealing ring through conduction. Traditional rubber seals soften after being heated, which may cause the sealing ring in the piston to have different sealing effects when the piston is running and when it is not running. Summary of the Invention

[0004] The purpose of this invention is to provide a rubber ring for sealing pump truck pistons and its preparation method in order to solve the above-mentioned problems.

[0005] The present invention achieves the above objectives through the following technical solutions:

[0006] This invention provides a rubber ring for sealing a pump truck piston. The rubber ring consists of an inner ring and an outer ring, with the outer ring enclosing the inner ring. By weight, the outer ring is made from 62-75 parts polyurethane particles, 5-10 parts natural rubber, 2-5 parts coumarone-indene resin, 7-9 parts cycloalkane oil, and 4-12 parts graphite. The inner ring is made from 86-95 parts polyurethane particles, 1-3 parts tetrafluoroethylene micropowder, and 5-10 parts elastic microspheres.

[0007] The materials used to prepare the elastic microspheres, by weight, include 30-35 parts urea, 35-40 parts 37% formaldehyde aqueous solution, 20-25 parts PCM core material, 6-12 parts emulsifier, 5-10 parts acidic catalyst, 60-72 parts deionized water, and 10-14 parts protective colloid.

[0008] As a further optimization of the present invention, the preparation process of the elastic microspheres is as follows: deionized water, emulsifier and protective colloid are added to the reactor and stirred until dissolved; PCM core material is added to the aqueous phase and sheared for 5-10 minutes at 10000-15000 rpm using a high-speed shearing machine to obtain an emulsion; the rotation speed of the emulsion is adjusted to 200-300 rpm, urea is added and stirred to dissolve, and then the pH is adjusted to 3.5-4 using an acidic catalyst; 37% formaldehyde aqueous solution is added dropwise, and the temperature is slowly raised to 55-60℃. At this temperature, the rotation speed is maintained at 200-300 rpm for 2-4 hours; the mixture is naturally cooled to room temperature, and the product is washed with deionized water until the filtrate is neutral. The filter cake is dried in a vacuum oven at 40-50℃ for 24 hours to obtain elastic microspheres.

[0009] As a further optimization of the present invention, the PCM core material is n-octadecane.

[0010] As a further optimization of the present invention, the protective colloid is either polyvinyl alcohol (PVA) or sodium hyaluronate.

[0011] As a further optimization of the present invention, the raw materials for preparing the emulsifier, by weight, include 15-20 parts Tween 80, 6-12 parts Span 80, 5-8 parts lecithin and 55-70 parts purified water.

[0012] As a further optimization of the present invention, the preparation process of the emulsifier is as follows: Tween 80 and Span 80 are mixed evenly, and then lecithin is added and stirred at 35 r / min for 30 min, and heated to 70°C; purified water is added and stirred at 15 r / min for 30 min to obtain a pre-formulated material; the pre-formulated material is added to a shear homogenizer and homogenized at 7000-10000 rpm for 3-5 min to obtain the emulsifier.

[0013] As a further optimization of the present invention, the acidic catalyst is either phosphoric acid or formic acid.

[0014] This invention also provides a method for preparing a rubber ring for a pump truck piston seal, comprising the following steps:

[0015] S1. Dry the polyurethane particles in an oven at 70-80℃ for 2-4 hours to remove moisture;

[0016] S2, add polyurethane particles, tetrafluoroethylene micro powder and elastic microspheres into the stirring mechanism and stir at 65r / min for 5min to obtain mixture A;

[0017] S3. Fill the mixture A into the preheated 180℃ sealing ring mold cavity, apply a pressure of 10-20 MPa, keep it warm and pressurized for 5-15 minutes, demold and cool to obtain the inner ring;

[0018] S4, add polyurethane and natural rubber into a stirring mechanism and stir at 65r / min for 5min, then set aside to obtain a blend;

[0019] S5, add cycloalkane oil and graphite into a stirring mechanism and stir at 120 r / min for 10 min to obtain a graphite-cycloalkane oil paste.

[0020] S6, the blend, graphite-cycloalkane paste and coumarone-indene resin are mixed evenly to obtain mixture B;

[0021] S7. Wrap the mixture B around the outside of the inner ring, fill it into the sealing ring mold cavity preheated to 160℃, apply a pressure of 10-20 MPa, keep it warm and pressurized for 5-15 minutes, demold and cool to obtain the rubber ring.

[0022] The beneficial effects of this invention are as follows: The rubber ring prepared by the double-layer functional partition design of the outer ring wrapping the inner ring has good support, high elasticity sealing and heat resistance. The inner ring is made of polyurethane + tetrafluoroethylene micro powder + elastic microspheres: as the core support layer, relying on the high strength and high tear resistance of polyurethane itself, combined with the wear resistance of tetrafluoroethylene micro powder and the deformation buffering capacity of elastic microspheres, it ensures that the rubber ring is not easily deformed or damaged under pressure and friction, providing stable mechanical support for the overall structure; the outer layer is made of polyurethane + natural rubber + stone Graphite-cycloalkane oil paste + coumarone-indene resin: As a functional layer, the high elasticity of natural rubber enhances the flexible sealing ability of the outer layer, allowing it to tightly adhere to the sealing surface and reduce gaps; the graphite in the graphite-cycloalkane oil paste provides long-lasting solid lubrication, while the naphthenic oil reduces the coefficient of friction and decreases wear between the outer ring and the sealing surface; coumarone-indene resin acts as a tackifier and reinforcing agent, further optimizing the adhesion and structural stability of the outer layer, preventing it from detaching or cracking during long-term use. The rubber ring in this invention can be widely used for mechanical piston seals. Detailed Implementation

[0023] The present application will now be described in further detail. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0024] Example 1

[0025] The preparation process of elastic microspheres is as follows: 65 parts of deionized water, 8 parts of emulsifier and 12 parts of polyvinyl alcohol (PVA) are added to the reactor and stirred until dissolved; 23 parts of n-octadecane are added to the aqueous phase and sheared at 15,000 rpm for 8 minutes to obtain an emulsion; the emulsion speed is adjusted to 260 rpm, 32 parts of urea are added and stirred until dissolved, and then the pH is adjusted to 3.5 with phosphoric acid; 37 parts of 37% formaldehyde aqueous solution are added dropwise, the temperature is slowly raised to 58℃, and the reaction is carried out at 240 rpm for 3 hours; the product is naturally cooled to room temperature, and the product is washed with deionized water until the filtrate is neutral. The filter cake is dried in a vacuum oven at 45℃ for 24 hours to obtain elastic microspheres.

[0026] The emulsifier was prepared as follows: 18 parts of Tween 80 and 10 parts of Span 80 were mixed evenly, and then 6 parts of lecithin were added and stirred at 35 r / min for 30 min, and heated to 70℃; 65 parts of purified water were added and stirred at 15 r / min for 30 min to obtain a pre-mixed material; the pre-mixed material was added to a shear homogenizer and homogenized at 8500 rpm for 4 min to obtain the emulsifier.

[0027] The polyurethane granules were dried in an oven at 75°C for 3 hours to remove moisture.

[0028] 87 parts of polyurethane particles, 2 parts of tetrafluoroethylene micro powder and 9 parts of elastic microspheres were added to a stirring mechanism and stirred at 65 r / min for 5 min to obtain mixture A.

[0029] Fill the preheated sealing ring mold cavity with mixture A into the mold cavity at 180°C, apply a pressure of 17 MPa, keep it warm and pressurized for 12 minutes, demold and cool to obtain the inner ring;

[0030] Add 70 parts of polyurethane granules and 8 parts of natural rubber to a mixing device and stir at 65 r / min for 5 min to obtain a blend.

[0031] Eight parts of cycloalkane oil and ten parts of graphite were added to a stirring device and stirred at 120 r / min for 10 min to obtain a graphite-cycloalkane oil paste.

[0032] The blend, graphite-cycloalkane paste, and 4 parts of coumarone-indene resin were mixed evenly to obtain mixture B;

[0033] The mixture B is wrapped around the outside of the inner ring and filled into the sealing ring mold cavity preheated to 160°C. A pressure of 15MPa is applied, and the temperature and pressure are maintained for 9 minutes. After demolding and cooling, the rubber ring is obtained.

[0034] Example 2

[0035] The preparation process of the elastic microspheres is as follows: 65 parts of deionized water, 8 parts of emulsifier and 12 parts of sodium hyaluronate are added to the reactor and stirred until dissolved; 23 parts of n-octadecane are added to the aqueous phase and sheared at 15000 rpm for 8 min using a high-speed shearing machine to obtain an emulsion; the speed of the emulsion is adjusted to 260 rpm, 32 parts of urea are added and stirred until dissolved, and then the pH is adjusted to 3.5 with phosphoric acid; 37 parts of 37% formaldehyde aqueous solution are added dropwise, the temperature is slowly raised to 58℃, and the speed is maintained at 240 rpm at this temperature for 3 h; the product is naturally cooled to room temperature, and the product is washed with deionized water until the filtrate is neutral. The filter cake is dried in a vacuum oven at 45℃ for 24 h to obtain elastic microspheres.

[0036] The emulsifier was prepared as follows: 18 parts of Tween 80 and 10 parts of Span 80 were mixed evenly, and then 6 parts of lecithin were added and stirred at 35 r / min for 30 min, and heated to 70℃; 65 parts of purified water were added and stirred at 15 r / min for 30 min to obtain a pre-mixed material; the pre-mixed material was added to a shear homogenizer and homogenized at 8500 rpm for 4 min to obtain the emulsifier.

[0037] The polyurethane granules were dried in an oven at 75°C for 3 hours to remove moisture.

[0038] 87 parts of polyurethane particles, 2 parts of tetrafluoroethylene micro powder and 9 parts of elastic microspheres were added to a stirring mechanism and stirred at 65 r / min for 5 min to obtain mixture A.

[0039] Fill the preheated sealing ring mold cavity with mixture A into the mold cavity at 180°C, apply a pressure of 17 MPa, keep it warm and pressurized for 12 minutes, demold and cool to obtain the inner ring;

[0040] Add 70 parts of polyurethane granules and 8 parts of natural rubber to a mixing device and stir at 65 r / min for 5 min to obtain a blend.

[0041] Eight parts of cycloalkane oil and ten parts of graphite were added to a stirring device and stirred at 120 r / min for 10 min to obtain a graphite-cycloalkane oil paste.

[0042] The blend, graphite-cycloalkane paste, and 4 parts of coumarone-indene resin were mixed evenly to obtain mixture B;

[0043] The mixture B is wrapped around the outside of the inner ring and filled into the sealing ring mold cavity preheated to 160°C. A pressure of 15MPa is applied, and the temperature and pressure are maintained for 9 minutes. After demolding and cooling, the rubber ring is obtained.

[0044] Example 3

[0045] The preparation process of elastic microspheres is as follows: 65 parts of deionized water, 8 parts of emulsifier and 12 parts of polyvinyl alcohol (PVA) are added to the reactor and stirred until dissolved; 23 parts of n-octadecane are added to the aqueous phase and sheared at 15,000 rpm for 8 minutes to obtain an emulsion; the emulsion speed is adjusted to 260 rpm, 32 parts of urea are added and stirred until dissolved, and then the pH is adjusted to 3.5 with formic acid; 37 parts of 37% formaldehyde aqueous solution are added dropwise, the temperature is slowly raised to 58℃, and the reaction is carried out at 240 rpm for 3 hours; the product is naturally cooled to room temperature, and the product is washed with deionized water until the filtrate is neutral. The filter cake is dried in a vacuum oven at 45℃ for 24 hours to obtain elastic microspheres.

[0046] The emulsifier was prepared as follows: 18 parts of Tween 80 and 10 parts of Span 80 were mixed evenly, and then 6 parts of lecithin were added and stirred at 35 r / min for 30 min, and heated to 70℃; 65 parts of purified water were added and stirred at 15 r / min for 30 min to obtain a pre-mixed material; the pre-mixed material was added to a shear homogenizer and homogenized at 8500 rpm for 4 min to obtain the emulsifier.

[0047] The polyurethane granules were dried in an oven at 75°C for 3 hours to remove moisture.

[0048] 87 parts of polyurethane particles, 2 parts of tetrafluoroethylene micro powder and 9 parts of elastic microspheres were added to a stirring mechanism and stirred at 65 r / min for 5 min to obtain mixture A.

[0049] Fill the preheated sealing ring mold cavity with mixture A into the mold cavity at 180°C, apply a pressure of 17 MPa, keep it warm and pressurized for 12 minutes, demold and cool to obtain the inner ring;

[0050] Add 70 parts of polyurethane granules and 8 parts of natural rubber to a mixing device and stir at 65 r / min for 5 min to obtain a blend.

[0051] Eight parts of cycloalkane oil and ten parts of graphite were added to a stirring device and stirred at 120 r / min for 10 min to obtain a graphite-cycloalkane oil paste.

[0052] The blend, graphite-cycloalkane paste, and 4 parts of coumarone-indene resin were mixed evenly to obtain mixture B;

[0053] The mixture B is wrapped around the outside of the inner ring and filled into the sealing ring mold cavity preheated to 160°C. A pressure of 15MPa is applied, and the temperature and pressure are maintained for 9 minutes. After demolding and cooling, the rubber ring is obtained.

[0054] Comparative Example 1

[0055] The polyurethane granules were dried in an oven at 75°C for 3 hours to remove moisture.

[0056] 96 parts of polyurethane granules and 2 parts of tetrafluoroethylene micro powder were added to a stirring mechanism and stirred at 65 r / min for 5 min to obtain mixture A;

[0057] Fill the preheated sealing ring mold cavity with mixture A into the mold cavity at 180°C, apply a pressure of 17 MPa, keep it warm and pressurized for 12 minutes, demold and cool to obtain the inner ring;

[0058] Add 70 parts of polyurethane granules and 8 parts of natural rubber to a mixing device and stir at 65 r / min for 5 min to obtain a blend.

[0059] Eight parts of cycloalkane oil and ten parts of graphite were added to a stirring device and stirred at 120 r / min for 10 min to obtain a graphite-cycloalkane oil paste.

[0060] The blend, graphite-cycloalkane paste, and 4 parts of coumarone-indene resin were mixed evenly to obtain mixture B;

[0061] The mixture B is wrapped around the outside of the inner ring and filled into the sealing ring mold cavity preheated to 160°C. A pressure of 15MPa is applied, and the temperature and pressure are maintained for 9 minutes. After demolding and cooling, the rubber ring is obtained.

[0062] Comparative Example 2

[0063] The preparation process of elastic microspheres is as follows: 65 parts of deionized water, 8 parts of emulsifier and 12 parts of polyvinyl alcohol (PVA) are added to the reactor and stirred until dissolved; 23 parts of n-octadecane are added to the aqueous phase and sheared at 15,000 rpm for 8 minutes to obtain an emulsion; the emulsion speed is adjusted to 260 rpm, 32 parts of urea are added and stirred until dissolved, and then the pH is adjusted to 3.5 with phosphoric acid; 37 parts of 37% formaldehyde aqueous solution are added dropwise, the temperature is slowly raised to 58℃, and the reaction is carried out at 240 rpm for 3 hours; the product is naturally cooled to room temperature, and the product is washed with deionized water until the filtrate is neutral. The filter cake is dried in a vacuum oven at 45℃ for 24 hours to obtain elastic microspheres.

[0064] The emulsifier was prepared as follows: 18 parts of Tween 80 and 10 parts of Span 80 were mixed evenly, and then 6 parts of lecithin were added and stirred at 35 r / min for 30 min, and heated to 70℃; 65 parts of purified water were added and stirred at 15 r / min for 30 min to obtain a pre-mixed material; the pre-mixed material was added to a shear homogenizer and homogenized at 8500 rpm for 4 min to obtain the emulsifier.

[0065] The polyurethane granules were dried in an oven at 75°C for 3 hours to remove moisture.

[0066] 87 parts of polyurethane particles and 11 parts of elastic microspheres were added to a stirring mechanism and stirred at 65 r / min for 5 min to obtain mixture A;

[0067] Fill the preheated sealing ring mold cavity with mixture A into the mold cavity at 180°C, apply a pressure of 17 MPa, keep it warm and pressurized for 12 minutes, demold and cool to obtain the inner ring;

[0068] Add 70 parts of polyurethane granules and 8 parts of natural rubber to a mixing device and stir at 65 r / min for 5 min to obtain a blend.

[0069] Eight parts of cycloalkane oil and ten parts of graphite were added to a stirring device and stirred at 120 r / min for 10 min to obtain a graphite-cycloalkane oil paste.

[0070] The blend, graphite-cycloalkane paste, and 4 parts of coumarone-indene resin were mixed evenly to obtain mixture B;

[0071] The mixture B is wrapped around the outside of the inner ring and filled into the sealing ring mold cavity preheated to 160°C. A pressure of 15MPa is applied, and the temperature and pressure are maintained for 9 minutes. After demolding and cooling, the rubber ring is obtained.

[0072] Comparative Example 3

[0073] The preparation process of elastic microspheres is as follows: 65 parts of deionized water, 8 parts of emulsifier and 12 parts of polyvinyl alcohol (PVA) are added to the reactor and stirred until dissolved; 23 parts of n-octadecane are added to the aqueous phase and sheared at 15,000 rpm for 8 minutes to obtain an emulsion; the emulsion speed is adjusted to 260 rpm, 32 parts of urea are added and stirred until dissolved, and then the pH is adjusted to 3.5 with phosphoric acid; 37 parts of 37% formaldehyde aqueous solution are added dropwise, the temperature is slowly raised to 58℃, and the reaction is carried out at 240 rpm for 3 hours; the product is naturally cooled to room temperature, and the product is washed with deionized water until the filtrate is neutral. The filter cake is dried in a vacuum oven at 45℃ for 24 hours to obtain elastic microspheres.

[0074] The emulsifier was prepared as follows: 18 parts of Tween 80 and 10 parts of Span 80 were mixed evenly, and then 6 parts of lecithin were added and stirred at 35 r / min for 30 min, and heated to 70℃; 65 parts of purified water were added and stirred at 15 r / min for 30 min to obtain a pre-mixed material; the pre-mixed material was added to a shear homogenizer and homogenized at 8500 rpm for 4 min to obtain the emulsifier.

[0075] The polyurethane granules were dried in an oven at 75°C for 3 hours to remove moisture.

[0076] 87 parts of polyurethane particles, 2 parts of tetrafluoroethylene micro powder and 9 parts of elastic microspheres were added to a stirring mechanism and stirred at 65 r / min for 5 min to obtain mixture A.

[0077] Add 70 parts of polyurethane granules and 8 parts of natural rubber to a mixing device and stir at 65 r / min for 5 min to obtain a blend.

[0078] Eight parts of cycloalkane oil and ten parts of graphite were added to a stirring device and stirred at 120 r / min for 10 min to obtain a graphite-cycloalkane oil paste.

[0079] The blend, graphite-cycloalkane paste, and 4 parts of coumarone-indene resin were mixed evenly to obtain mixture B;

[0080] Mix mixture A and mixture B evenly, fill the preheated sealing ring mold cavity at 160℃, apply a pressure of 15MPa, keep warm and pressurized for 9 minutes, demold and cool to obtain the rubber ring.

[0081] Performance testing

[0082] ①The hardness of the rubber rings prepared by the methods in Examples 1-3 and Comparative Examples 1-3 was tested according to GB / T 6031-1998 "Determination of hardness of vulcanized rubber or thermoplastic rubber".

[0083] ②The tensile strength and elongation at break of the rubber rings prepared by the methods of Examples 1-3 and Comparative Examples 1-3 were tested in accordance with GB / T 528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber".

[0084] ③ GB / T 7758-2020 "Determination of Low-Temperature Properties of Vulcanized Rubber" tests the low-temperature brittleness of the rubber rings prepared by the methods in Examples 1-3 and Comparative Examples 1-3.

[0085] The test results are as follows

[0086] Table 1

[0087]

[0088] ④ The compression set of the rubber rings prepared by the methods in Examples 1-3 and Comparative Examples 1-3 was tested according to GB / T 7759.2-2014 "Determination of Compression Set of Vulcanized Rubber or Thermoplastic Rubber" (test conditions: 100℃×70h).

[0089] ⑤ The rubber rings prepared by the methods of Examples 1-3 and Comparative Examples 1-3 were tested for changes in performance after hot air aging in accordance with GB / T 3512-2014 "Accelerated aging and heat resistance test of vulcanized rubber or thermoplastic rubber in hot air". The change in tensile strength was recorded as A and the change in elongation was recorded as B (test conditions: 120℃×70h).

[0090] ⑥ The resistance to liquid volume change of the rubber rings prepared by the methods of Examples 1-3 and Comparative Examples 1-3 were tested according to GB / T 1690-2010 "Test Method for Liquid Resistance of Vulcanized Rubber or Thermoplastic Rubber" (test conditions: machine oil, 100℃×70h).

[0091]

[0092] As can be seen from the table above, the invention adopts a dual-layer structure with the inner ring providing core support and the outer ring providing outer protection. The two layers complement each other, solving the contradiction that a single material cannot simultaneously meet the requirements of high-strength support and flexible sealing.

[0093] The inner ring is made of polyurethane + PTFE micro powder + elastic microspheres: as the core support layer, relying on the high strength and high tear resistance of polyurethane itself, combined with the wear resistance of PTFE micro powder and the deformation buffering capacity of elastic microspheres, it ensures that the rubber ring is not easily deformed or damaged under pressure and friction scenarios, providing stable mechanical support for the overall structure.

[0094] The outer layer is made of polyurethane + natural rubber + graphite-naphthenic oil paste + coumarone-indene resin: As a functional layer, the high elasticity of natural rubber enhances the flexible sealing ability of the outer layer, allowing it to fit tightly to the sealing surface and reduce gaps; the graphite in the graphite-naphthenic oil paste provides long-lasting solid lubrication, while the naphthenic oil reduces the coefficient of friction and reduces wear between the outer ring and the sealing surface; coumarone-indene resin acts as a tackifier and reinforcing agent, further optimizing the adhesion and structural stability of the outer layer and preventing it from peeling off or cracking during long-term use.

[0095] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A rubber ring for sealing a pump truck piston, characterized in that, The rubber ring is divided into an inner ring and an outer ring, with the outer ring enclosing the inner ring. By weight, the outer ring is prepared from 62-75 parts polyurethane particles, 5-10 parts natural rubber, 2-5 parts coumarone-indene resin, 7-9 parts cycloalkane oil, and 4-12 parts graphite. The inner ring is prepared from 86-95 parts polyurethane particles, 1-3 parts tetrafluoroethylene micropowder, and 5-10 parts elastic microspheres. The materials used to prepare the elastic microspheres, by weight, include 30-35 parts urea, 35-40 parts 37% formaldehyde aqueous solution, 20-25 parts PCM core material, 6-12 parts emulsifier, 5-10 parts acidic catalyst, 60-72 parts deionized water, and 10-14 parts protective colloid.

2. The rubber ring for sealing a pump truck piston according to claim 1, characterized in that, The preparation process of the elastic microspheres is as follows: deionized water, emulsifier, and protective colloid are added to the reactor and stirred until dissolved; PCM core material is added to the aqueous phase and sheared at 10,000-15,000 rpm for 5-10 minutes to obtain an emulsion; the rotation speed of the emulsion is adjusted to 200-300 rpm, urea is added, stirred and dissolved, and then the pH is adjusted to 3.5-4 with an acidic catalyst; 37% formaldehyde aqueous solution is added dropwise, the temperature is slowly raised to 55-60℃, and the rotation speed is maintained at 200-300 rpm at this temperature for 2-4 hours; the product is naturally cooled to room temperature, and the product is washed with deionized water until the filtrate is neutral. The filter cake is dried in a vacuum oven at 40-50℃ for 24 hours to obtain elastic microspheres.

3. The rubber ring for sealing a pump truck piston according to claim 2, characterized in that, The PCM core material is n-octadecane.

4. The rubber ring for sealing a pump truck piston according to claim 2, characterized in that, The protective colloid is either polyvinyl alcohol (PVA) or sodium hyaluronate.

5. A rubber ring for sealing a pump truck piston according to claim 2, characterized in that, The raw materials for preparing the emulsifier, by weight, include 15-20 parts Tween 80, 6-12 parts Span 80, 5-8 parts lecithin, and 55-70 parts purified water.

6. A rubber ring for sealing a pump truck piston according to claim 5, characterized in that, The preparation process of the emulsifier is as follows: Tween 80 and Span 80 are mixed evenly, and then lecithin is added and stirred at 35 r / min for 30 min, and heated to 70℃; purified water is added and stirred at 15 r / min for 30 min to obtain a pre-formulated material; the pre-formulated material is added to a shear homogenizer and homogenized at 7000-10000 rpm for 3-5 min to obtain the emulsifier.

7. A rubber ring for sealing a pump truck piston according to claim 2, characterized in that, The acidic catalyst is either phosphoric acid or formic acid.

8. A method for preparing a rubber ring for sealing a pump truck piston according to any one of claims 1-7, characterized in that, Includes the following steps: S1. Dry the polyurethane particles in an oven at 70-80℃ for 2-4 hours to remove moisture; S2, add polyurethane particles, tetrafluoroethylene micro powder and elastic microspheres into the stirring mechanism and stir at 65r / min for 5min to obtain mixture A; S3. Fill the mixture A into the preheated 180℃ sealing ring mold cavity, apply a pressure of 10-20 MPa, keep it warm and pressurized for 5-15 minutes, demold and cool to obtain the inner ring; S4, add polyurethane and natural rubber into a stirring mechanism and stir at 65r / min for 5min, then set aside to obtain a blend; S5, add cycloalkane oil and graphite into a stirring mechanism and stir at 120 r / min for 10 min to obtain graphite-cycloalkane oil paste; S6, the blend, graphite-cycloalkane paste and coumarone-indene resin are mixed evenly to obtain mixture B; S7. Wrap the mixture B around the outside of the inner ring, fill it into the sealing ring mold cavity preheated to 160℃, apply a pressure of 10-20MPa, keep it warm and pressurized for 5-15 minutes, demold and cool to obtain the rubber ring.

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