A rubber hose for a liquid cooling system and a manufacturing method thereof

Abstract

The present invention discloses a rubber compound for preparing a rubber hose for a liquid cooling system, which is made of raw materials including the following parts by weight: 55 to 80 parts of high Mooney ethylene propylene diene monomer (EPDM) rubber, 20 to 45 parts of low Mooney EPDM rubber, 100 to 150 parts of fast extruding carbon black, 30 to 65 parts of paraffin oil, 3 to 8 parts of petroleum resin, 1 to 5 parts of antioxidant, 2 to 7 parts of adhesive, 3 to 8 parts of zinc oxide, 1 to 3 parts of stearic acid, 0.3 to 1.5 parts of sulfur, and 3 to 8 parts of accelerator. The present invention also discloses a rubber hose for a liquid cooling system, which sequentially includes an inner rubber layer, a first reinforcing layer, a first intermediate rubber layer, a second reinforcing layer, a second intermediate rubber layer, a third reinforcing layer, and an outer rubber layer from inside to outside. The hose has excellent flexibility, a smaller bending radius, improves the flexibility and efficiency of the space layout of the liquid cooling system, and has good compatibility with electronic fluorinated liquid, excellent high and low temperature resistance, ozone resistance and other properties, and has excellent durability.

Description

Technical Field

[0001] The present invention belongs to the field of rubber composite processing, and relates to a rubber compound for a rubber hose used in a liquid cooling system, in particular to an inner layer, a middle layer and an outer layer rubber compound for a rubber hose used in a liquid cooling system, and a rubber hose used in a liquid cooling system made of the rubber compound. Background Art

[0002] With the development of technologies such as artificial intelligence, cloud computing, big data, and blockchain, the 5G communication era featuring high speed, low latency, and large connection has arrived. The requirements for heat dissipation in fields such as AI computing power, data centers, and semiconductors are getting higher and higher, and traditional air cooling, water cooling, etc. have been difficult to meet the demands. Against this background, liquid cooling technology, with its characteristics such as ultra-high energy efficiency and ultra-high heat density, is gradually becoming the focus of industry attention and the key path to solve the heat dissipation bottleneck and energy-saving challenges.

[0003] The commonly used medium types in liquid cooling systems are diverse, including deionized water, alcohol-based solutions, fluorocarbon-based working fluids, mineral oils, or silicone oils, etc. Among them, electronic fluorinated liquid, as a new type of cooling medium, is colorless, odorless, non-oil-based, and non-corrosive, and has a wide operating temperature range, low toxicity, excellent chemical stability, and excellent dielectric properties. Due to its unique performance advantages, electronic fluorinated liquid occupies an important position in liquid cooling systems that pursue high efficiency, safety, and environmental protection, and has become the preferred medium in high-end liquid cooling and special application fields.

[0004] In the prior art, metal cooling pipes made of materials such as copper and aluminum, although excellent in thermal conductivity, have inherent defects such as poor toughness and large bending radius, which not only limit the flexibility of the cooling pipe in spatial layout, but also are prone to stress concentration, deformation, and even leakage due to the significant thermal expansion and contraction effect, thereby shortening the service life of the cooling pipe and affecting the overall performance of the system. Therefore, developing a new type of cooling pipe for liquid cooling systems has become an urgent technical problem to be solved. Summary of the Invention

[0005] The purpose of the present invention is to innovate the hose formula and structure in consideration of comprehensive properties such as flexibility, bending performance, high and low temperature resistance, etc. aiming at the deficiencies of existing cooling pipes in liquid cooling systems, and provide a rubber compound for preparing a cooling pipe and a rubber hose for a liquid cooling system made of the rubber compound. The hose not only has excellent flexibility, a small bending radius, good compatibility with electronic fluorinated liquid, but also is resistant to high and low temperatures, can effectively resist the stress influence caused by temperature changes, has a long service life, and can ensure the long-term, safe, and reliable operation of the liquid cooling system.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A rubber compound for preparing a rubber hose for a liquid cooling system is made from raw materials including the following parts by weight: 55 to 80 parts of high Mooney ethylene propylene diene monomer (EPDM) rubber, 20 to 45 parts of low Mooney EPDM rubber, 100 to 150 parts of fast extruding carbon black, 30 to 65 parts of paraffin oil, 3 to 8 parts of petroleum resin, 1 to 5 parts of antioxidant, 2 to 7 parts of adhesive, 3 to 8 parts of zinc oxide, 1 to 3 parts of stearic acid, 0.3 to 1.5 parts of sulfur, 3 to 8 parts of accelerator; wherein the total parts by weight of the high Mooney EPDM rubber and the low Mooney EPDM rubber is 100 parts.

[0008] Preferably, the rubber compound for preparing a rubber hose for a liquid cooling system is made from raw materials including the following parts by weight: 60 to 75 parts of high Mooney EPDM rubber, 25 to 40 parts of low Mooney EPDM rubber, 120 to 140 parts of fast extruding carbon black, 40 to 60 parts of paraffin oil, 4 to 6 parts of petroleum resin, 2 to 4 parts of antioxidant, 3 to 5 parts of adhesive, 3 to 8 parts of zinc oxide, 1 to 3 parts of stearic acid, 0.3 to 1 part of sulfur, 4 to 6 parts of accelerator.

[0009] The Mooney viscosity ML(1+4)125℃ of the high Mooney EPDM rubber is 70 to 90, the ethylene content is 45% to 55%, and the content of the third monomer ethylidene norbornene is 5.0% to 6.0%; the Mooney viscosity ML(1+4)125℃ of the low Mooney EPDM rubber is 30 to 45, the ethylene content is 45% to 55%, and the content of the third monomer ethylidene norbornene is 4.0% to 5.0%.

[0010] The paraffin oil is paraffin oil SUNPAR 2280; the petroleum resin is petroleum resin HC52110; the adhesive is adhesive RC.

[0011] The antioxidant is at least one of antioxidant MB and antioxidant RD, preferably a combination of antioxidant MB and antioxidant RD in a mass ratio of 1:1.

[0012] The accelerator is at least one of accelerator TMTD, accelerator DPTT, accelerator BZ, and accelerator DTDM, preferably a combination of accelerator DTDM, accelerator TMTD, accelerator DPTT, and accelerator BZ in a mass ratio of 1:(1 to 2):(2 to 3):(2 to 3).

[0013] Another object of the present invention is to provide a preparation method of the rubber compound for preparing a rubber hose for a liquid cooling system, including the following steps:

[0014] Step (1), the internal mixer is cooled by water, the temperature of the working chamber of the internal mixer is controlled not to exceed 50°C, and the high Mooney EPDM rubber, low Mooney EPDM rubber, zinc oxide, stearic acid, and antioxidant are added and kneaded for 1 to 2 minutes.

[0015] Step (2): Add fast extrusion carbon black, paraffin oil, petroleum resin and binder, and knead for 2 - 4 min;

[0016] Step (3): Add sulfur and accelerator, knead for 0.5 - 2 min, and discharge the rubber when the temperature of the internal mixer rises to 110 °C;

[0017] Step (4): Transfer the rubber compound to an open mill for thin passing and sheeting, and let it stand for 8 hours to obtain the rubber compound for preparing the rubber hose for the liquid cooling system.

[0018] Another object of the present invention is to provide a rubber hose for a liquid cooling system, which sequentially includes an inner rubber layer, a first reinforcing layer, a first middle rubber layer, a second reinforcing layer, a second middle rubber layer, a third reinforcing layer, and an outer rubber layer from inside to outside; the inner rubber layer, the first middle rubber layer, the second middle rubber layer, and the outer rubber layer are all extruded from the rubber compound described in claim 1; the first reinforcing layer and the third reinforcing layer are woven from polyester threads; the second reinforcing layer is wound with copper-plated steel wires.

[0019] The thickness of the inner rubber layer is 2.0 - 2.4 mm; the thickness of the first middle rubber layer is 0.3 - 0.5 mm; the thickness of the second middle rubber layer is 0.4 - 0.6 mm; the thickness of the outer rubber layer is 2.0 - 2.4 mm; the first reinforcing layer and the third reinforcing layer are both woven from polyester threads in a 36-spindle 2-strand weaving method, and the coverage rate is 80 - 90%; the second reinforcing layer is wound with copper-plated steel wires, and the pitch is 6 - 8 mm.

[0020] Another object of the present invention is to provide a preparation method for a rubber hose for a liquid cooling system, including: inner layer rubber extrusion, polyester thread weaving, first middle layer rubber compound extrusion, copper-plated steel wire winding, second middle layer rubber compound extrusion, polyester thread weaving, outer layer rubber extrusion, cloth winding, vulcanization, cloth unwinding, core removal, and inspection processes; wherein the vulcanization pressure is 0.4 - 0.6 MPa, the vulcanization temperature is 150 ± 5 °C, and the vulcanization time is 60 ± 2 min.

[0021] The present invention uses a combination of a high Mooney viscosity ethylene propylene diene monomer (EPDM) rubber with a Mooney viscosity ML(1+4) 125 °C of 70 - 90, an ethylene content of 45% - 55%, and a third monomer ethylidene norbornene content of 5.0% - 6.0% and a low Mooney viscosity EPDM rubber with a Mooney viscosity ML(1+4) 125 °C of 30 - 45, an ethylene content of 45% - 55%, and a third monomer ethylidene norbornene content of 4.0% - 5.0%. It not only has good processing performance, but also enables the rubber compound to have higher filling capacity, better strength and molding stiffness, and at the same time has good compatibility with electronic fluorinated liquid.

[0022] The present invention selects the environmentally friendly paraffin oil SUNPAR 2280 as a plasticizer, which has a high saturated hydrocarbon content, a stable molecular weight, a high flash point, good compatibility with ethylene propylene diene monomer (EPDM) rubber, and a relatively small odor, and can improve the processing performance and high temperature resistance of the rubber compound.

[0023] The petroleum resin HC52110 belongs to the C5 / C9 copolymer type petroleum resin and has a low odor and good thermal stability. The binder RC is a complex compound based on melamine and belongs to the meta - tol - white bonding system, with the dual functions of both a methylene donor and a methylene acceptor. The present invention selects the combined use of petroleum resin HC52110 and binder RC, which can endow the rubber compound with good adhesiveness and improve the adhesion strength between the rubber compound and the fiber - reinforced layer and the copper - plated steel wire.

[0024] The present invention uses two anti - aging agents, anti - aging agent MB and anti - aging agent RD, in combination, which has a good "synergistic effect" and can endow the rubber compound with excellent heat - aging resistance, ozone - resistance and other properties.

[0025] The present invention selects carbon black N550 as a reinforcing filler. Carbon black N550 has a medium particle size, a relatively high structure, low heat generation and good thermal conductivity, and can endow the rubber compound with good processing performance and physical and mechanical properties.

[0026] The vulcanization system of the present invention uses sulfur in combination with accelerator TMTD, accelerator DPTT, accelerator BZ, and accelerator DTDM, which can significantly improve the cross - linking degree of the rubber compound and endow it with excellent physical and mechanical properties, high and low temperature resistance and other properties.

[0027] The beneficial effects of the present invention:

[0028] The present invention selects the combined use of high - Mooney and low - Mooney EPDM rubbers, uses anti - aging agent MB and anti - aging agent RD in combination, uses paraffin oil SUNPAR 2280, and by adding petroleum resin HC52110 and binder RC, not only endows the rubber compound with good physical and mechanical properties, high and low temperature resistance, ozone - resistance, but also has good compatibility with electronic fluorinated liquid.

[0029] The rubber hose for the liquid - cooling system made of the rubber compound of the present invention has excellent flexibility, a small bending radius, and good adhesion between the layers of the hose, excellent high and low temperature resistance, ozone - resistance and other properties, and has excellent durability, with a service life of up to 15 years. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic structural diagram of the rubber hose for the liquid - cooling system of the present invention.

[0031] Figure 1 In the figure, 1 - inner rubber layer; 2 - first reinforcing layer; 3 - first intermediate rubber layer; 4 - second reinforcing layer; 5 - second intermediate rubber layer; 6 - third reinforcing layer; 7 - outer rubber layer. Detailed implementation manners

[0032] The technical solution of the present invention will be further described below through specific implementation manners.

[0033] Table 1. Rubber compound formulation

[0034]

[0035] Example 1

[0036] The raw materials and dosages of the rubber compound in this example are shown in Table 1 and are prepared in the following manner:

[0037] Step (1), the internal mixer is cooled with water, and the temperature of the internal mixer working chamber is controlled not to exceed 50 °C. Add high Mooney ethylene propylene diene monomer rubber, low Mooney ethylene propylene diene monomer rubber, zinc oxide, stearic acid and antioxidant, and knead for 1.5 min;

[0038] Step (2), add fast extruded carbon black, paraffin oil, petroleum resin and binder, and knead for 3 min;

[0039] Step (3), add sulfur and accelerator, knead for 1 min, and discharge the rubber when the temperature of the internal mixer rises to 110 °C;

[0040] Step (4), transfer the rubber compound to an open mill for thin-sheeting and standing for 8 hours to obtain the rubber compound for preparing the rubber hose for the liquid cooling system.

[0041] Example 2

[0042] The raw materials and dosages of the rubber compound in this example are shown in Table 1, and the preparation method is the same as that of Example 1.

[0043] Example 3

[0044] The raw materials and dosages of the rubber compound in this example are shown in Table 1, and the preparation method is the same as that of Example 1.

[0045] Comparative Example 1

[0046] The raw materials and dosages of the rubber compound in this comparative example are shown in Table 1. Compared with Example 2, Comparative Example 1 does not use ethylene propylene diene monomer rubber Keltan 4450S (low Mooney ethylene propylene diene monomer rubber), but due to the too high Mooney viscosity of the rubber compound, normal kneading cannot be carried out according to the preparation method of Example 1.

[0047] Comparative Example 2

[0048] The raw materials and dosages of the rubber compound in this comparative example are shown in Table 1. Compared with Example 2, Comparative Example 2 does not use ethylene propylene diene monomer rubber Keltan 8550C (high Mooney ethylene propylene diene monomer rubber), and the preparation method is the same as that of Example 1.

[0049] Comparative Example 3

[0050] The raw materials and their dosages of the rubber compound in this comparative example are shown in Table 1. Compared with Example 2, petroleum resin HC52110 was not used in Comparative Example 3, and the preparation method was the same as that of Example 1.

[0051] Comparative Example 4

[0052] The raw materials and their dosages of the rubber compound in this comparative example are shown in Table 1. Compared with Example 2, adhesive RC was not used in Comparative Example 4, and the preparation method was the same as that of Example 1.

[0053] The properties of the rubber compounds prepared in Examples 1 - 3 and Comparative Examples 2 - 4 were investigated, and experiments were carried out in accordance with the standards "GB / T531.1 - 2008", "GB / T 528 - 2009", and "GB / T 1690 - 2010". The results are shown in Table 2.

[0054] Table 2. Rubber compound performance parameters

[0055]

[0056] Example 4

[0057] As Figure 1 shown, a rubber hose for a liquid cooling system was prepared according to Table 3, which successively included an inner rubber layer 1, a first reinforcing layer 2, a first middle rubber layer 3, a second reinforcing layer 4, a second middle rubber layer 5, a third reinforcing layer 6, and an outer rubber layer 7 from the inside to the outside. The preparation method of the rubber hose for the liquid cooling system was as follows, including the following steps:

[0058] Step (1): Feed the rubber compound by a cold feeder and extrude it with a φ25.0 mm mandrel to obtain an inner rubber layer with a thickness of 2.6 mm; weave it with 36 spindles and 2 strands to obtain a first reinforcing layer with a coverage rate of 85%.

[0059] Step (2): Extrude the rubber compound to cover the outside of the first reinforcing layer to obtain a first middle rubber layer with a thickness of 0.4 mm; wind it with copper - plated steel wires to obtain a second reinforcing layer.

[0060] Step (3): Extrude the rubber compound to cover the outside of the second reinforcing layer to obtain a second middle rubber layer with a thickness of 0.5 mm; weave it with 36 spindles and 2 strands to obtain a third reinforcing layer with a coverage rate of 80%.

[0061] Step (4): Extrude the rubber compound to cover the outside of the third reinforcing layer to obtain an outer rubber layer with a thickness of 1.8 mm; form a tube blank after winding cloth.

[0062] Step (5): Vulcanize the tube blank at a temperature of 150 °C and a pressure of 0.5 MPa for 60 min; obtain the rubber hose for the liquid cooling system after unwinding the cloth, removing the mandrel, and inspection.

[0063] Table 4. Hose structure

[0064]

[0065] The hose performance is as follows:

[0066] Table 4. Hose Performance

[0067]

[0068] It can be seen from Comparative Example 3 and Comparative Example 4 that when petroleum resin HC52110 and adhesive RC are not used simultaneously in the formulation, although the physical and mechanical properties of the rubber compound and its compatibility with the electronic fluorinated liquid change little, the adhesion strength between the layers of the hose made from the corresponding rubber compound decreases significantly. It can be seen that petroleum resin HC52110 and adhesive RC need to be compounded to make the hose have excellent adhesion performance, and the good adhesion between the layers of the hose can ensure the integrity and long service life of the hose. The rubber compound in Comparative Example 2 uses a single low Mooney ethylene propylene diene monomer (EPDM), and both the physical and mechanical properties of the rubber compound and its compatibility with the electronic fluorinated liquid are poor. The stiffness of the hose made from this rubber compound is poor, and the bending performance cannot meet the requirements. When the hose structure lacks a copper-plated steel wire winding layer or the pitch is not within the required range, the bending performance is poor. In addition, the hose of the present invention is first bent around a mandrel with a diameter twice the outer diameter, and then tests such as bending performance, temperature cycle, and ozone resistance are carried out, and the test results are good. As is well known, the minimum bending radius of a general rubber hose is 5 to 8 times the nominal outer diameter, while the minimum bending radius of the rubber hose for the liquid cooling system of the present invention is smaller, even less than twice the outer diameter of the hose.

[0069] The above embodiments are only used to help understand the method and its core idea of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A rubber compound for preparing a rubber hose for a liquid cooling system, characterized in that: It is made of the following raw materials in parts by weight: 55-80 parts of high Mooney EPDM rubber, 20-45 parts of low Mooney EPDM rubber, 100-150 parts of quick-extrusion carbon black, 30-65 parts of paraffin oil, 3-8 parts of petroleum resin, 1-5 parts of antioxidant, 2-7 parts of adhesive, 3-8 parts of zinc oxide, 1-3 parts of stearic acid, 0.3-1.5 parts of sulfur, and 3-8 parts of accelerator; wherein the total weight of the high Mooney EPDM rubber and the low Mooney EPDM rubber is 100 parts; The high Mooney EPDM rubber has a Mooney viscosity ML (1+4) of 70 to 90 at 125°C, an ethylene content of 45% to 55%, and a third monomer ethylidene norbornene content of 5.0% to 6.0%; the low Mooney EPDM rubber has a Mooney viscosity ML (1+4) of 30 to 45 at 125°C, an ethylene content of 45% to 55%, and a third monomer ethylidene norbornene content of 4.0% to 5.0%; The paraffin oil is paraffin oil SUNPAR 2280; the petroleum resin is petroleum resin HC52110; and the adhesive is adhesive RC.

2. The rubber material for preparing a rubber hose for a liquid cooling system according to claim 1, characterized in that: The rubber material used for preparing the rubber hose for the liquid cooling system is made of the following raw materials in parts by weight: 60 to 75 parts of high Mooney EPDM rubber, 25 to 40 parts of low Mooney EPDM rubber, 120 to 140 parts of quick-extrusion carbon black, 40 to 60 parts of paraffin oil, 4 to 6 parts of petroleum resin, 2 to 4 parts of antioxidant, 3 to 5 parts of adhesive, 3 to 8 parts of zinc oxide, 1 to 3 parts of stearic acid, 0.3 to 1 part of sulfur, and 4 to 6 parts of accelerator.

3. The rubber material for preparing a rubber hose for a liquid cooling system according to claim 1 or 2, characterized in that: The antioxidant is at least one of antioxidant MB and antioxidant RD; the accelerator is at least one of accelerator TMTD, accelerator DPTT, accelerator BZ and accelerator DTDM.

4. A rubber compound for preparing a rubber hose for a liquid cooling system according to claim 1 or 2, characterized in that: The antioxidant is a combination of antioxidant MB and antioxidant RD in a mass ratio of 1:1; the accelerator is a combination of accelerator DTDM, accelerator TMTD, accelerator DPTT and accelerator BZ in a mass ratio of 1:(1-2):(2-3):(2-3).

5. A method for preparing a rubber compound for preparing a rubber hose for a liquid cooling system according to claim 1 or 2, characterized in that: The following steps are involved: Step (1), cooling the internal mixer with water, controlling the temperature of the internal mixer working room to not exceed 50° C., adding high Mooney EPDM rubber, low Mooney EPDM rubber, zinc oxide, stearic acid and antioxidant, and mixing for 1 to 2 minutes; Step (2), adding quick-pressed carbon black, paraffin oil, petroleum resin and adhesive, and mixing for 2 to 4 minutes; Step (3), adding sulfur and accelerator, mixing for 0.5 to 2 minutes, and then draining after the temperature of the internal mixer rises to 110°C; Step (4), moving the rubber material to an open mixing mill for thinning, and leaving it to stand for 8 hours to obtain a rubber material for preparing a rubber hose for a liquid cooling system.

6. A rubber hose for a liquid cooling system, characterized in that: From the inside to the outside, it includes an inner rubber layer, a first reinforcement layer, a first middle rubber layer, a second reinforcement layer, a second middle rubber layer, a third reinforcement layer, and an outer rubber layer; the inner rubber layer, the first middle rubber layer, the second middle rubber layer, and the outer rubber layer are all made by extruding the rubber material described in claim 1; the first reinforcement layer and the third reinforcement layer are woven by polyester wire; the second reinforcement layer is wound by copper-plated steel wire.

7. The rubber hose for liquid cooling system according to claim 6, characterized in that: The thickness of the inner rubber layer is 2.0-3.0 mm; the thickness of the first middle rubber layer is 0.3-0.5 mm; the thickness of the second middle rubber layer is 0.4-0.6 mm; the thickness of the outer rubber layer is 1.5-2.5 mm; the first reinforcement layer and the third reinforcement layer are both woven from polyester wire using a 36-spindle 2-strand weaving method, with a coverage rate of 80-90%; the second reinforcement layer is wound with copper-plated steel wire, with a pitch of 6-8 mm.

8. A method for preparing the rubber hose for a liquid cooling system according to claim 6, characterized in that: include: The process includes inner layer rubber extrusion, polyester wire braiding, first middle layer rubber extrusion, copper-plated steel wire winding, second middle layer rubber extrusion, polyester wire braiding, outer layer rubber extrusion, cloth winding, vulcanization, cloth unwinding, core removal and inspection. The vulcanization pressure is 0.4-0.6MPa, the vulcanization temperature is 150±5℃ and the vulcanization time is 60±2min.

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