High-temperature-resistant low-pressure-change damping material and manufacturing process thereof

Abstract

The invention provides a high-temperature-resistant low-pressure-change shock-absorbing material and a manufacturing process of the high-temperature-resistant low-pressure-change shock-absorbing material. The rubber composition comprises the following components in parts by mass: 190 parts of oil-extended EPDM (100 parts of oil / 100 parts of rubber), 5 parts of natural rubber, 30-80 parts of carbon black, 30-100 parts of an inorganic reinforcing agent, 5-20 parts of white carbon black, 70-100 parts of high-flash-point paraffin oil, 5 parts of zinc oxide, 3-10 parts of magnesium oxide, 1 part of stearic acid, 1-2 parts of polyethylene glycol, 1-4 parts of a heat-resistant anti-aging agent, 0.2-0.8 part of sulfur and 4-7 parts of an accelerant. The anti-aging agent and the high-flash-point paraffin oil are added into the shock-absorbing material, so that the consumption of sulfur is reduced on the premise that the original physical properties and low pressure change performance of the shock-absorbing material are kept, the heat-resistant temperature of the shock-absorbing material is further increased to 145 DEG C, and the hardness change does not exceed + 8A under the thermal oxidation condition of 145 DEG C.

Description

Technical Field

[0001] The present application relates to the technical field of polymer compound compositions, and in particular to a high temperature resistant and low pressure variable shock absorbing material and a manufacturing process thereof. Background Art

[0002] In order to improve the production efficiency and feasibility of compressor shock-absorbing rubber parts in the home appliance air-conditioning industry, such rubber parts all use sulfur as a vulcanizing agent. The rubber parts have limited heat resistance. Specifically, under hot oxygen conditions of 145°C, the hardness changes by more than +8A, causing the shock-absorbing effect of the shock-absorbing rubber parts to weaken or even fail. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a high temperature resistant low pressure change damping material which is beneficial to improving the heat resistance performance, and the technical solution adopted includes:

[0004] A high temperature resistant and low pressure change damping material, characterized in that it comprises, by mass:

[0005]

[0006]

[0007] The technical solution adopted by an embodiment of the present invention to solve the technical problem is: the flash point of the high flash point paraffin oil is greater than 270°C.

[0008] The technical solution adopted by an embodiment of the present invention to solve the technical problem is: EPDM with medium or low ENB content is selected.

[0009] The technical solution adopted by an embodiment of the present invention to solve the technical problem is: the ENB content in the EPDM is 4-5.5%.

[0010] The technical solution adopted by an embodiment of the present invention to solve the technical problem is: the heat-resistant antioxidant is one or two of RD and MB.

[0011] This application also proposes a manufacturing process for the above-mentioned high temperature resistant and low pressure damping material, and the technical solutions adopted include:

[0012] Step 1: Put EPDM, natural rubber, carbon black, inorganic reinforcing agent, white carbon black, magnesium oxide, zinc oxide, stearic acid, polyethylene glycol, and heat-resistant antioxidant into an internal mixer at the same time, with a hammer pressure of 6kg, and mix at a temperature of 90-110°C for 60-90s.

[0013] Half lift the heavy hammer to clean and then press down, and continue mixing for 30-40 seconds;

[0014] The weight is lifted to the highest point, held for 5 seconds, and then pressed down, and mixing is continued for at least 30 to 60 seconds. After the temperature reaches 130 to 150°C, the rubber is discharged to obtain a mixed rubber;

[0015] Step 2: adding sulfur and accelerator into the mixed rubber, mixing and then producing sheets, and vulcanizing twice to obtain the shock absorbing material.

[0016] The technical solution adopted by an embodiment of the present invention to solve the technical problem is: the primary vulcanization in step 2 is 170±5°C and the vulcanization time is 330s.

[0017] The technical solution adopted by an embodiment of the present invention to solve the technical problem is: the secondary vulcanization temperature in step 2 is 150° C. and the vulcanization time is 2 hours.

[0018] Beneficial effects of the present invention:

[0019] The present application adds antioxidants and high flash point paraffin oil to the shock-absorbing material to ensure that the shock-absorbing material maintains its original physical properties and low pressure change performance, while reducing the amount of sulfur used, thereby increasing the heat resistance temperature of the shock-absorbing material to 145°C, and under hot oxygen conditions at 145°C, the hardness change does not exceed +8A. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0021] Figure 1 A cross-sectional view of the shock-absorbing washer described in the present application before compression;

[0022] Figure 2 This is a schematic diagram of the structure of the compression device described in this application;

[0023] Figure 3 This is a cross-sectional view of the shock-absorbing washer described in this application after compression. DETAILED DESCRIPTION

[0024] The terms used in the present invention, unless otherwise specified, generally have the meanings commonly understood by those of ordinary skill in the art.

[0025] The present invention is further described in detail below in conjunction with specific examples and with reference to data. It should be understood that this embodiment is only for illustrating the present invention and is not intended to limit the scope of the present invention in any way.

[0026] In the following examples, various processes and methods not described in detail are conventional methods known in the art. The materials, reagents, devices, instruments, equipment, etc. used in the following examples, unless otherwise specified, can be obtained from commercial sources.

[0027] Comparative Example

[0028] The comparative example proposes an existing shock-absorbing rubber material, which comprises, by weight:

[0029]

[0030] The preparation process of the shock-absorbing rubber material in Comparative Example 1 includes:

[0031] Step 1, oil-filled EPDM, natural rubber, carbon black, white carbon black, softening oil, zinc oxide, stearic acid, polyethylene glycol, and heat-resistant antioxidant are all put into an internal mixer at the same time, with a hammer pressure of 6 kg and a mixing time of 60 seconds at 100°C;

[0032] Half lift the hammer, press down after cleaning and continue mixing for 30 seconds;

[0033] The weight is raised to the highest position, held for 5 seconds, then pressed down and continued to mix for 30 seconds. After the mixing temperature rises to 140°C, the rubber is discharged to obtain a mixed rubber;

[0034] Step 2: Add sulfur and accelerator into the rubber mix, mix and form a sheet, add it into a mold, perform primary vulcanization at a temperature of 165-175° C. for 330 seconds, then cool to 150° C. for secondary vulcanization for 2 hours to obtain a shock-absorbing gasket.

[0035] Example 1

[0036] This embodiment provides a shock-absorbing rubber material, which includes, by weight:

[0037]

[0038] Example 2

[0039] This embodiment provides a shock-absorbing rubber material, which includes, by weight:

[0040] Example 3

[0041] This embodiment 3 proposes a shock-absorbing rubber material, which includes, by weight:

[0042]

[0043]

[0044] The steps for preparing the shock-absorbing rubber material in Examples 1-3 include:

[0045] Step 1, EPDM, natural rubber, carbon black, inorganic reinforcing agent, white carbon black, magnesium oxide, zinc oxide, stearic acid, polyethylene glycol, and heat-resistant antioxidant are all put into an internal mixer at the same time, with a hammer pressure of 6 kg and a mixing time of 60 seconds at 100°C;

[0046] Half lift the hammer, press down after cleaning and continue mixing for 30 seconds;

[0047] The weight is raised to the highest position, held for 5 seconds, then pressed down and continued to mix for 30 seconds. After the mixing temperature rises to 140°C, the rubber is discharged to obtain a mixed rubber;

[0048] Step 2: Add sulfur and accelerator into the rubber mix, mix and form a sheet, add it into a mold, perform primary vulcanization at a temperature of 165-175° C. for 330 seconds, then cool to 150° C. for secondary vulcanization for 2 hours to obtain a shock-absorbing gasket.

[0049] In the embodiments and comparative examples of the present application:

[0050] EPDM adopts ARLANXEO's 4869C;

[0051] The softening oil in Comparative Example 1 is: polyisobutylene;

[0052] The high flash point paraffin oil in the embodiment is derived from Xinjiang Karamay paraffin oil;

[0053] The heat-resistant antioxidant is RD;

[0054] The accelerator is one or more of CZ, M, TT, BZ, TBZTD, S, and DTDM. In this embodiment, CZ is selected;

[0055] The inorganic reinforcing agent is nano-aluminum silicate, brand 6851;

[0056] The physical properties of the shock-absorbing washers obtained in Example 1 and the comparative example were tested, and the test results and test standards are shown in Table 1.

[0057] Table 1

[0058]

[0059] In this application, the method for detecting the compression permanent invariance rate is:

[0060] The rubber damping material obtained in the comparative example and the embodiment is made into Figure 1 The shock-absorbing washer shown in the figure has a shoulder height of t. Measure the shoulder height t of the shock-absorbing washer before the test, and then install the shock-absorbing washer in the Figure 2 After being uniformly compressed by 30% on the compression device shown in the figure, it is placed in an oven at (100±2)℃ for 72 hours, taken out from the oven, and conditioned in an environment of temperature 23℃±2℃ and humidity 50%±10% for 4h to 16h. The vibration-damping gasket is taken out of the compression device and the shoulder height t1 of the compressed shock-damping gasket is measured.

[0061] Refer to the attached Figure 2 As shown, the compression device includes two pressing plates spaced apart and connected to each other, and a plurality of cushion blocks are arranged between the two pressing plates, and the thickness t2 of the cushion blocks is 70%*t;

[0062] The compression permanent deformation invariance rate standard of the shock-absorbing gasket is determined by the compression permanent deformation invariance rate requirement: K ≥ 80%. The calculation method is as follows:

[0063]

[0064] Where: t——shoulder height of the shock-absorbing washer before the test, mm;

[0065] t1——shoulder height of the shock-absorbing washer after the test, mm.

[0066] According to the test results in Table 1, the rubber damping material of Example 1 maintains the same level of hardness, tensile strength and compression permanent rate as the rubber damping material in the prior art at room temperature, and its elongation at break is better than that of the rubber damping material in the prior art.

[0067] The rubber damping material in the prior art changes its hardness to +6HA under the condition of 125°C hot oxygen, and the rubber damping material in Example 1 changes its hardness to +4HA under the condition of 125°C hot oxygen;

[0068] The hardness of the rubber shock-absorbing material in the prior art changes to +10HA under hot oxygen conditions at 145°C, while the hardness of the rubber shock-absorbing material finished product of Example 1 changes to +4HA under hot oxygen conditions at 145°C, which complies with GB / T3512-2001, indicating that the rubber shock-absorbing material of Example 1 has better heat resistance than the rubber shock-absorbing material in the prior art.

[0069] Of course, the present invention is not limited to the above-mentioned embodiments, and those skilled in the art may make equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications and substitutions are all included in the scope defined by the claims of this application.

Claims

1. A high temperature resistant and low pressure damping material, characterized in that: Included by mass:

2. The high temperature resistant and low pressure damping material according to claim 1, characterized in that: The flash point of the high flash point paraffin oil is greater than 270°C.

3. The high temperature resistant and low pressure damping material according to claim 1, characterized in that: EPDM uses EPDM with medium or low ENB content.

4. The high temperature resistant and low pressure damping material according to claim 3, characterized in that: The ENB content in the EPDM is 4-5.5%.

5. The high temperature resistant and low pressure change damping material according to claim 1, characterized in that: The heat-resistant antioxidant is one or two of RD and MB.

6. A process for manufacturing the high temperature resistant and low pressure damping material according to claim 1, characterized in that: include: Step 1: Put EPDM, natural rubber, carbon black, inorganic reinforcing agent, white carbon black, magnesium oxide, zinc oxide, stearic acid, polyethylene glycol, and heat-resistant antioxidant into an internal mixer at the same time, with a hammer pressure of 6kg, and mix at a temperature of 90-110°C for 60-90s. Half lift the heavy hammer to clean and then press down, and continue mixing for 30-40 seconds; The weight is lifted to the highest point, held for 5 seconds, and then pressed down, and mixing is continued for at least 30 to 60 seconds. After the temperature reaches 130 to 150°C, the rubber is discharged to obtain a mixed rubber; Step 2: adding sulfur and accelerator into the mixed rubber, mixing and then producing sheets, and vulcanizing twice to obtain the shock absorbing material.

7. The manufacturing process of the high temperature resistant and low pressure damping material according to claim 6 is characterized in that: The primary vulcanization temperature in step 2 is 170±5°C and the vulcanization time is 330s.

8. The manufacturing process of the high temperature resistant and low pressure damping material according to claim 6 is characterized in that: The secondary vulcanization temperature in step 2 is 150°C and the vulcanization time is 2 hours.

Images