A hose material for cooling of large data center equipment and a method of making the same

Abstract

The application relates to the technical field of rubber, and discloses a soft tube material for cooling of a large data center device and a preparation method thereof. The soft tube material is prepared by the following steps: plasticizing terpolymer ethylene-propylene-diene rubber in an open mill, then adding polyurethane elastomer, reinforcing agent, filling oil and the like for mixing, finally adding vulcanizing agent and crosslinking agent for mixing, thin passing and vulcanization. The crosslinking agent contains a non-polar long carbon chain, can reduce the affinity between the soft tube material and polar solvents such as ethylene glycol, thereby reducing the solubility and swelling rate of the soft tube material, and the soft tube material has excellent ethylene glycol resistance. The crosslinking agent contains a large amount of ester groups, can improve the compatibility of the terpolymer ethylene-propylene-diene rubber with the polyester type polyurethane elastomer, makes the polyurethane elastomer have better reinforcing and toughening effects, further improves the mechanical properties of the soft tube material, and the soft tube material has the advantages of high tensile strength and elongation at break and low compression permanent set.

Description

Technical Field

[0001] This invention relates to the field of rubber technology, specifically to a material for a cooling hose for big data center equipment and its preparation method. Background Technology

[0002] Ethylene propylene diene monomer (EPDM) rubber possesses excellent resistance to high and low temperatures, electrical insulation, and abrasion resistance, making it widely used in cable materials, cooling circulation pipes, sealing strips, and waterproof membranes. Cooling circulation hoses are closed-loop pipes used to transport circulating coolants such as ethylene glycol and water, facilitating heat transfer between equipment and radiators, controlling temperature, and preventing overheating. They are primarily used in data server equipment, generator sets, and automotive engines. Improving the solvent resistance of cooling circulation hoses reduces the corrosive and dissolving effects of coolants like ethylene glycol on the hoses, thus maintaining good mechanical properties and extending their service life.

[0003] To improve the mechanical and weather resistance properties of EPDM rubber, peroxides and alkenyl crosslinking agents can be used for crosslinking modification, such as N,N'-m-phenyl bismaleimide, triallyl isocyanurate, and trimethylolpropane trimethacrylate. However, these crosslinking agents cannot effectively improve the resistance of EPDM rubber to ethylene glycol and other properties. Summary of the Invention

[0004] (I) Technical problem to be solved: In view of the shortcomings of the existing technology, the present invention provides a material for cooling hoses for big data center equipment and its preparation method, which solves the problems of poor resistance to ethylene glycol and mechanical properties of EPDM rubber.

[0005] (II) Technical solution: A hose material comprising EPDM rubber, polyurethane elastomer, reinforcing agent, filler oil, zinc oxide, stearic acid, accelerator, antioxidant, vulcanizing agent, and crosslinking agent in a mass ratio of 100:(3-10):(30-40):(32-40):(3-5):(1.3-2):(1.9-2.5):(1.2-1.6):(2.4-2.7):(2.5-3.2).

[0006] The preparation method of the hose material is as follows:

[0007] (1) Add glyceryl dimethacrylate and triethylamine to dichloromethane, add acyl chloride compound dropwise in an ice bath, stir the reaction and filter, evaporate the filtrate by rotary evaporation, and separate the crude product by column chromatography to obtain the crosslinking agent. The reaction formula is:

[0008] .

[0009] (2) The EPDM rubber is plasticized in an open mill, and then polyurethane elastomer, reinforcing agent, filler oil, zinc oxide, stearic acid, accelerator and antioxidant are added and mixed. Finally, vulcanizing agent and crosslinking agent are added, mixed, thinly passed, and sheeted. The sheet is placed in a flat vulcanizing machine for vulcanization to obtain hose material.

[0010] Furthermore, filler oils include naphthenic oils and paraffin oils.

[0011] Furthermore, reinforcing agents include silica and calcium carbonate.

[0012] Furthermore, the vulcanizing agent is dicumyl peroxide or bis-tert-butylperoxide.

[0013] Furthermore, the accelerators include accelerator CZ, accelerator TMTD, accelerator M, and accelerator BZ.

[0014] Furthermore, the antioxidants are antioxidant 4010, antioxidant NBC, and antioxidant 264.

[0015] Furthermore, in (1), the molar ratio of glyceryl dimethacrylate, triethylamine, and acyl chloride compounds is (2-2.6):(2-2.2):1; the acyl chloride compounds include sebacate chloride, undecanediol chloride, and dodecanediol chloride.

[0016] Furthermore, the reaction in (1) is stirred at 20-25°C for 60-72 hours.

[0017] Furthermore, the vulcanization temperature is 165-175℃, the pressure is 8-10MPa, and the vulcanization time is 8-15min.

[0018] Furthermore, a fiber braided skeleton layer can be provided in the hose material, and the fibers include polyester fiber, nylon fiber, and aramid fiber.

[0019] Furthermore, the application of hose materials in the cooling of big data center equipment.

[0020] (III) Beneficial technical effects: By blending and vulcanizing EPDM rubber, polyurethane elastomer, crosslinking agent, vulcanizing agent, etc., a hose material for equipment cooling is obtained. The crosslinking agent contains multiple alkenyl groups, which undergo a crosslinking reaction with EPDM rubber during high-temperature vulcanization, which can improve the degree of crosslinking of EPDM rubber and improve the mechanical, heat resistance, solvent resistance and other properties of the rubber hose material.

[0021] The crosslinking agent of this invention contains non-polar long carbon chains, which can reduce the affinity between the hose material and polar solvents such as ethylene glycol, thereby reducing the solubility and swelling rate of the hose material and exhibiting excellent resistance to ethylene glycol. The crosslinking agent contains a large number of ester groups, which, when introduced into EPDM rubber, can improve its compatibility with polyester-type polyurethane elastomers, giving the polyurethane elastomers better reinforcing and toughening effects, further improving the mechanical properties of the hose material, resulting in high tensile strength and elongation at break, and low compression set. Detailed Implementation

[0022] To further explain the technical solution of the present invention, the present invention will be described in detail below through specific embodiments.

[0023] Example 1:

[0024] (1) Add 192 mmol of glyceryl dimethacrylate and 160 mmol of triethylamine to 350 mL of dichloromethane. Add sebacyl chloride and 80 mmol of sebacyl chloride dropwise in an ice bath. Stir the reaction at 20 °C for 72 h. Filter the mixture and evaporate the filtrate by rotary evaporation. Separate the crude product by column chromatography to obtain the crosslinking agent.

[0025] (2) 1 kg of EPDM rubber (model Dow EPDM 3722P, Shanghai Yiqiang Plastic Technology Co., Ltd., the same below) was plasticized in an open mill. Then, 30 g of polyurethane elastomer (model polyester polyurethane S90A55, Dongguan Jiurui Plastic Raw Materials Co., Ltd., the same below), 250 g of silica, 100 g of calcium carbonate, 370 g of naphthenic oil, 30 g of zinc oxide, 15 g of stearic acid, 13 g of accelerator M, 9 g of accelerator BZ, and 12 g of antioxidant 264 were added and mixed. Finally, 24 g of dicumyl peroxide and 25 g of crosslinking agent were added, mixed, thinned, and sheeted. The sheet was placed in a flat vulcanizing machine for vulcanization for 10 min at a temperature of 170°C and a pressure of 10 MPa to obtain hose material.

[0026] Example 2:

[0027] (1) Add 160 mmol of glyceryl dimethacrylate and 176 mmol of triethylamine to 350 mL of dichloromethane. Add sebacyl chloride and 80 mmol of dodecanoic acid chloride dropwise in an ice bath. Stir the reaction at 20 °C for 72 h. Filter the mixture and evaporate the filtrate by rotary evaporation. Separate the crude product by column chromatography to obtain the crosslinking agent.

[0028] (2) 1 kg of EPDM rubber was plasticized in an open mill, and then 50 g of polyurethane elastomer, 200 g of silica, 100 g of calcium carbonate, 320 g of naphthenic oil, 50 g of zinc oxide, 13 g of stearic acid, 14 g of accelerator CZ, 11 g of accelerator TMTD, and 13 g of antioxidant 4010 were added and mixed. Finally, 27 g of di-tert-butylperoxyisopropylbenzene and 32 g of crosslinking agent were added, mixed, thinned, and sheeted. The sheet was placed in a flat vulcanizing machine for vulcanization for 15 min at a temperature of 165°C and a pressure of 10 MPa to obtain hose material.

[0029] Example 3:

[0030] (1) Add 208 mmol of glyceryl dimethacrylate and 176 mmol of triethylamine to 350 mL of dichloromethane. Add sebacyl chloride and 80 mmol of sebacyl chloride dropwise in an ice bath. Stir the reaction at 25 °C for 60 h. Filter the mixture and evaporate the filtrate by rotary evaporation. Separate the crude product by column chromatography to obtain the crosslinking agent.

[0031] (2) 1 kg of EPDM rubber was plasticized in an open mill, and then 80 g of polyurethane elastomer, 250 g of silica, 150 g of calcium carbonate, 380 g of paraffin oil, 40 g of zinc oxide, 15 g of stearic acid, 13 g of accelerator CZ, 9 g of accelerator TMTD, and 12 g of antioxidant NBC were added and mixed. Finally, 25 g of dicumyl peroxide and 30 g of crosslinking agent were added, mixed, thinned, and sheeted. The sheet was placed in a flat vulcanizing machine for vulcanization for 8 min at a temperature of 175 °C and a pressure of 8 MPa to obtain hose material.

[0032] Example 4:

[0033] (1) Add 192 mmol of glyceryl dimethacrylate and 176 mmol of triethylamine to 350 mL of dichloromethane. Add sebacate chloride and 80 mmol of sebacate chloride dropwise in an ice bath. Stir the reaction at 20 °C for 72 h. Filter the mixture and evaporate the filtrate by rotary evaporation. Separate the crude product by column chromatography to obtain the crosslinking agent.

[0034] (2) 1 kg of EPDM rubber was plasticized in an open mill, and then 100 g of polyurethane elastomer, 200 g of silica, 150 g of calcium carbonate, 400 g of paraffin oil, 40 g of zinc oxide, 16 g of stearic acid, 12 g of accelerator M, 7 g of accelerator BZ, and 16 g of antioxidant 4010 were added and mixed. Finally, 27 g of di-tert-butylperoxyisopropylbenzene and 28 g of crosslinking agent were added, mixed, thinned, and sheeted. The sheet was placed in a flat vulcanizing machine for vulcanization for 8 min at a temperature of 170°C and a pressure of 10 MPa to obtain hose material.

[0035] Comparative Example 1:

[0036] (1) 1 kg of EPDM rubber was plasticized in an open mill, and then 30 g of polyurethane elastomer, 250 g of silica, 100 g of calcium carbonate, 370 g of naphthenic oil, 30 g of zinc oxide, 15 g of stearic acid, 13 g of accelerator M, 9 g of accelerator BZ, and 12 g of antioxidant 264 were added and mixed. Finally, 24 g of dicumyl peroxide and 25 g of triallyl isocyanurate were added, mixed, thinned, and sheeted. The sheet was placed in a flat vulcanizing machine for vulcanization for 10 min at a temperature of 170°C and a pressure of 10 MPa to obtain hose material.

[0037] Comparative Example 2:

[0038] (1) 1 kg of EPDM rubber was plasticized in an open mill, and then 30 g of polyurethane elastomer, 250 g of silica, 100 g of calcium carbonate, 370 g of naphthenic oil, 30 g of zinc oxide, 15 g of stearic acid, 13 g of accelerator M, 9 g of accelerator BZ, and 12 g of antioxidant 264 were added and mixed. Finally, 24 g of dicumyl peroxide and 25 g of trimethylolpropane trimethacrylate were added, mixed, thinned, and sheeted. The sheet was placed in a flat vulcanizing machine for vulcanization for 10 min at a temperature of 170 °C and a pressure of 10 MPa to obtain hose material.

[0039] Comparative Example 3:

[0040] (1) Add 192 mmol of glyceryl dimethacrylate and 160 mmol of triethylamine to 350 mL of dichloromethane. Add sebacyl chloride and 160 mmol of decanoyl chloride dropwise in an ice bath. Stir the reaction at 20 °C for 72 h. Filter the mixture, evaporate the filtrate by rotary evaporation, and separate the crude product by column chromatography to obtain the crosslinking agent with the following structural formula: .

[0041] (2) 1 kg of EPDM rubber was plasticized in an open mill, and then 30 g of polyurethane elastomer, 250 g of silica, 100 g of calcium carbonate, 370 g of naphthenic oil, 30 g of zinc oxide, 15 g of stearic acid, 13 g of accelerator M, 9 g of accelerator BZ, and 12 g of antioxidant 264 were added and mixed. Finally, 24 g of dicumyl peroxide and 25 g of crosslinking agent were added, mixed, thinned, and sheeted. The sheet was placed in a flat vulcanizing machine for vulcanization for 10 min at a temperature of 170°C and a pressure of 10 MPa to obtain hose material.

[0042] Weigh the dried hose material (m0), immerse it in a 50% ethylene glycol aqueous solution, heat it to 50°C, and immerse it for 240 hours. Remove the hose material, clean off any residual ethylene glycol on the surface, wipe it dry, and weigh it (m1). Calculate the swelling rate W, W = (m1 - m0) / m0 × 100%.

[0043] The tensile properties of the hose material are tested according to standard GB / T 528-2009. The compression set is tested according to standard GB / T7759.1-2015.

[0044] Table 1 Properties of hose materials

[0045] Example 1 1.328 12.7 438.0 18.6 Example 2 0.847 14.1 412.6 16.8 Example 3 1.134 11.5 527.9 13.5 Example 4 0.959 14.6 384.7 19.3 Comparative Example 1 1.625 10.3 389.2 21.7 Comparative Example 2 1.690 12.3 425.4 19.8 Comparative Example 3 1.471 10.8 409.1 21.2

[0046] In each embodiment, a crosslinking agent containing multiple alkenyl groups is added to the EPDM rubber hose material. This agent undergoes a crosslinking reaction with the EPDM rubber during high-temperature vulcanization, increasing the degree of crosslinking and improving the mechanical, heat resistance, and solvent resistance properties of the rubber hose material. Simultaneously, the crosslinking agent contains non-polar long carbon chains, reducing the affinity between the hose material and polar solvents such as ethylene glycol, thereby reducing solubility and swelling rate. It exhibits excellent ethylene glycol resistance. Furthermore, the crosslinking agent contains a large number of ester groups, which, when introduced into the EPDM rubber, improve its compatibility with polyester-type polyurethane elastomers, giving the polyurethane elastomers better reinforcing and toughening effects. This further enhances the mechanical properties of the hose material, resulting in high tensile strength and elongation at break, and low compression set.

[0047] Comparative Example 1 uses conventional triallyl isocyanurate as a crosslinking agent. It does not contain non-polar long carbon chains, and the hose material has a large swelling rate in the polar solvent of ethylene glycol. It also does not contain ester groups and has poor compatibility with polyurethane elastomers. As a result, the tensile strength and elongation at break of the hose material are lower than those of Example 1, while the compression set is higher than that of Example 1.

[0048] Comparative Example 2's trimethylolpropane trimethacrylate does not contain nonpolar long carbon chains, and the hose material has a large swelling rate in the polar solvent ethylene glycol.

[0049] The crosslinking agent in Comparative Example 3 contains only two alkenyl groups, resulting in fewer crosslinking sites and poor crosslinking effect with EPDM rubber, leading to poor mechanical properties of the hose material.

[0050] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A flexible hose material, characterized in that, The hose material comprises EPDM rubber, polyurethane elastomer, reinforcing agent, filler oil, zinc oxide, stearic acid, accelerator, antioxidant, vulcanizing agent, and crosslinking agent in a mass ratio of 100:(3-10):(30-40):(32-40):(3-5):(1.3-2):(1.9-2.5):(1.2-1.6):(2.4-2.7):(2.5-3.2). The structural formula of the crosslinking agent is: , where a is 8-10.

2. The hose material according to claim 1, characterized in that, The filler oil is one or more of naphthenic oil and paraffin oil.

3. The hose material according to claim 1, characterized in that, The reinforcing agent is one or more of silica and calcium carbonate.

4. The hose material according to claim 1, characterized in that, The vulcanizing agent is one or more of dicumyl peroxide and bis-tert-butylperoxide.

5. The hose material according to claim 1, characterized in that, The accelerator is one or more of accelerator CZ, accelerator TMTD, accelerator M, and accelerator BZ.

6. The hose material according to claim 1, characterized in that, The antioxidant is one or more of antioxidant 4010, antioxidant NBC, and antioxidant 264.

7. A method for preparing a flexible tube material as described in any one of claims 1-6, characterized in that, The preparation method is as follows: (1) Add glyceryl dimethacrylate and triethylamine to dichloromethane, add acyl chloride compound dropwise in an ice bath, stir and react at 20-25℃ for 60-72h, filter, evaporate the filtrate by rotary evaporation, and separate the crude product by column chromatography to obtain the crosslinking agent; (2) The EPDM rubber is plasticized in an open mill, and then polyurethane elastomer, reinforcing agent, filler oil, zinc oxide, stearic acid, accelerator and antioxidant are added and mixed. Finally, vulcanizing agent and crosslinking agent are added, mixed, thinly passed, and sheeted. The sheet is placed in a flat vulcanizing machine for vulcanization to obtain hose material.

8. The method for preparing the hose material according to claim 7, characterized in that, The molar ratio of the dimethacrylate, triethylamine, and acyl chloride compound is (2-2.6):(2-2.2):1; the acyl chloride compound includes sebacate chloride, undecanediol chloride, and dodecanediol chloride.

9. The method for preparing the hose material according to claim 8, characterized in that, The vulcanization temperature is 165-175℃, the pressure is 8-10MPa, and the vulcanization time is 8-15min.

10. The application of a hose material obtained by the preparation method as described in claim 9 in the cooling of big data center equipment.

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