Anti-aging low-temperature chloroprene rubber composition and preparation method thereof

Abstract

The invention relates to an anti-aging low-temperature chloroprene rubber composition and a preparation method thereof, and belongs to the technical field of chloroprene rubber. The anti-aging low-temperature chloroprene rubber composition provided by the invention is prepared from the following components in parts by weight: 100 parts of chloroprene rubber, 10 to 30 parts of aconite, 10 to 20 parts of polyacrylate, 1 to 2 parts of stearic acid, 1 to 10 parts of magnesium oxide and 1 to 10 parts of zinc oxide. The chloroprene rubber composition not only has better aging resistance, but also has better cold resistance, the compatibility of the aconite and the chloroprene rubber can be improved by adding the polyacrylate, the difficulty that the aconite is separated from the chloroprene rubber is increased, and the toughness of the chloroprene rubber is obviously improved.

Description

Technical Field

[0001] The present application relates to an aging-resistant low-temperature chloroprene rubber composition and a preparation method thereof, belonging to the technical field of chloroprene rubber. Background Art

[0002] Chloroprene rubber (CR), also known as chloroprene rubber, is an elastomer produced by α-polymerization of chloroprene (i.e. 2-chloro-1,3-butadiene) as the main raw material. It is milky white, beige or light brown in the form of flakes or blocks, with a density of 1.23~1.25 g / cm 3 , glass transition temperature -40℃~-50℃, fragmentation point -35℃, softening point about 80℃, decomposition temperature 230~260℃, soluble in organic solvents such as chloroform and benzene, swells but does not dissolve in vegetable oil and mineral oil. It has good physical and mechanical properties, oil resistance, heat resistance, flame resistance, sunlight resistance, ozone resistance, acid and alkali corrosion resistance, and chemical reagent dissolution resistance, but the disadvantage is poor cold resistance and storage stability.

[0003] In the Chinese patent CN117510693A, the invention title is a method for improving the cold resistance of sulfur-adjusted chloroprene rubber. In order to improve the cold resistance of chloroprene rubber, aconitate is added to chloroprene rubber to improve the cold resistance of chloroprene rubber, and the brittle temperature is reduced from -35°C to -49°C. However, although the addition of aconitate improves the cold resistance, it leads to a significant reduction in the aging resistance of chloroprene rubber. Therefore, it is necessary to provide a chloroprene rubber with excellent aging resistance and cold resistance. Summary of the invention

[0004] In order to solve the above problems, an aging-resistant low-temperature chloroprene rubber composition and a preparation method thereof are provided. The chloroprene rubber composition provided in the present application not only has good aging resistance, but also has good cold resistance. The combination of aconitate and polyacrylate can improve the compatibility with chloroprene rubber and increase the difficulty of aconitate to be separated from chloroprene rubber, so that the toughness of chloroprene rubber is also significantly improved.

[0005] The present application provides an aging-resistant low-temperature chloroprene rubber composition, which comprises the following components in parts by weight: 100 parts of chloroprene rubber, 10 to 30 parts of aconitate, 10 to 20 parts of polyacrylate, 1 to 2 parts of stearic acid, 1 to 10 parts of magnesium oxide and 1 to 10 parts of zinc oxide.

[0006] Optionally, the aconitate ester is selected from one or more of tri-n-butyl aconitate, tri-n-pentyl aconitate, tri-n-hexyl aconitate, tri-n-heptyl aconitate, tri-n-octyl aconitate or tri(2-ethylhexyl) aconitate.

[0007] Optionally, the polyacrylate is selected from one or more of n-butyl polyacrylate, n-pentyl polyacrylate, n-hexyl polyacrylate, n-heptyl polyacrylate, n-octyl polyacrylate, or isooctyl acrylate.

[0008] Optionally, the molecular weight range of the polyacrylate is 10,000 - 200,000 g / mol.

[0009] Optionally, the molecular weight range of the polyacrylate is 20,000 - 100,000 g / mol.

[0010] Optionally, the chloroprene rubber is selected from one or more of sulfur-regulated type, non-sulfur-regulated type, or mixed-regulated type.

[0011] Optionally, when the chloroprene rubber is selected from non-sulfur-regulated type or mixed-regulated type, it further includes a thiourea accelerator. It should be noted that according to the characteristics and types of different chloroprene rubbers, those skilled in the art can add other necessary or performance-improving additives as needed, which is the basic ability of those skilled in the art.

[0012] Optionally, the thiourea accelerator is selected from one or more of NA-22, DETU, or DPTU.

[0013] Optionally, by weight, it includes the following components: 100 parts of non-sulfur-regulated chloroprene rubber, 10 - 30 parts of aconitic acid ester, 10 - 20 parts of polyacrylate, 1 - 2 parts of stearic acid, 1 - 10 parts of magnesium oxide, 1 - 10 parts of zinc oxide, and 1 - 5 parts of thiourea accelerator.

[0014] Optionally, by weight, it includes the following components: 100 parts of mixed-regulated chloroprene rubber, 10 - 30 parts of aconitic acid ester, 10 - 20 parts of polyacrylate, 1 - 2 parts of stearic acid, 1 - 10 parts of magnesium oxide, 1 - 10 parts of zinc oxide, and 1 - 5 parts of thiourea accelerator.

[0015] Optionally, by weight, it includes the following components: 100 parts of sulfur-regulated chloroprene rubber, 25 parts of aconitic acid ester, 15 parts of polyacrylate, 1.5 parts of stearic acid, 4 parts of magnesium oxide, and 5 parts of zinc oxide.

[0016] Optionally, by weight, it includes the following components: 100 parts of non-sulfur-regulated chloroprene rubber, 25 parts of aconitic acid ester, 15 parts of polyacrylate, 1.5 parts of stearic acid, 4 parts of magnesium oxide, 5 parts of zinc oxide, and 2.5 parts of thiourea accelerator.

[0017] Optionally, by weight, it includes the following components: 100 parts of mixed-regulated chloroprene rubber, 25 parts of aconitic acid ester, 15 parts of polyacrylate, 1.5 parts of stearic acid, 4 parts of magnesium oxide, 5 parts of zinc oxide, and 2.5 parts of thiourea accelerator.

[0018] According to one aspect of the present application, a preparation method of an aging-resistant low-temperature neoprene rubber composition is provided. The preparation method includes the following steps: 1) Weigh neoprene rubber, aconitic acid ester, and polyacrylate and add them to an open mill. The mixing temperature is 45-55°C, and the mixing time is 1-3 minutes; 2) Weigh stearic acid and add it to the open mill. The mixing temperature is 45-55°C, and the mixing time is 1-3 minutes; 3) Weigh magnesium oxide and zinc oxide, and add magnesium oxide and zinc oxide along the roller. The mixing temperature is 45-55°C, and the mixing time is 2-5 minutes; 4) Make 3 / 4 cuts alternately from each side 2-6 times; 5) Adjust the roller gap, and roll the mixed rubber into a coil and thin it longitudinally 4-8 times to obtain the aging-resistant low-temperature neoprene rubber.

[0019] Optionally, the preparation method includes the following steps: 1) Weigh neoprene rubber, aconitic acid ester, and polyacrylate and add them to an open mill. The mixing temperature is 50°C, and the mixing time is 1 minute; 2) Weigh stearic acid and add it to the open mill. The mixing temperature is 50°C, and the mixing time is 1 minute; 3) Weigh magnesium oxide and zinc oxide, and add magnesium oxide and zinc oxide along the roller. The mixing temperature is 50°C, and the mixing time is 2 minutes; 4) Make 3 / 4 cuts alternately from each side 3 times; 5) Adjust the roller gap, and roll the mixed rubber into a coil and thin it longitudinally 6 times to obtain the aging-resistant low-temperature neoprene rubber.

[0020] Optionally, the vulcanization method of the aging-resistant low-temperature neoprene rubber includes: vulcanizing the mixed rubber sample under the conditions of a vulcanization pressure of 10-20 Mpa and a vulcanization temperature of 140-180°C for 10-20 minutes.

[0021] The beneficial effects of the present application include but are not limited to: 1. According to the aging-resistant low-temperature neoprene rubber composition and its preparation method of the present application, in terms of improving cold resistance, aconitic acid ester and polyacrylate form a good synergistic effect. The blending of polyacrylate and neoprene rubber alone plays a certain role in improving toughness and low-temperature performance, but limited by poor compatibility, the improvement amplitude is not large; the blending of aconitic acid ester and neoprene rubber can effectively improve the cold resistance of the material. After blending the three in a certain proportion, aconitic acid ester can make polyacrylate and neoprene rubber completely compatible by virtue of its good compatibility with the two materials, increasing the increase of polyacrylate in terms of cold resistance and toughness for neoprene rubber. Especially in terms of cold resistance, aconitic acid ester not only improves the low-temperature brittleness of neoprene rubber but also increases the modification of polyacrylate on the low-temperature performance of neoprene rubber, making the neoprene rubber composite have good cold resistance.

[0022] 2. Regarding the anti-aging low-temperature type chloroprene rubber composition and its preparation method according to the present application, in terms of anti-aging, although the trans-aconitate alone can effectively improve the low-temperature performance of chloroprene rubber when modifying it, the intermolecular interaction force between the two is relatively small. Under high-temperature conditions, the aconitate is likely to migrate to the outside, resulting in poor anti-aging performance of the material. After introducing polyacrylate, on the one hand, the aconitate can make the polyacrylate completely compatible with chloroprene rubber, enhancing the modification effect; at the same time, the aconitate exists between the two materials of chloroprene rubber and polyacrylate, and has a stronger intermolecular interaction force with the blended matrix material, which can effectively reduce the outward migration of the aconitate and improve the thermal stability and anti-aging performance of the material.

[0023] 3. Regarding the anti-aging low-temperature type chloroprene rubber composition and its preparation method according to the present application, the aconitate not only acts as a low-temperature modifier and plasticizer, but also serves as a compatibilizer for polyacrylate to make it completely compatible with chloroprene rubber. The blend shows a single glass transition temperature, which is beneficial for the material to maintain better softness at low temperatures.

[0024] 4. Regarding the anti-aging low-temperature type chloroprene rubber composition and its preparation method according to the present application, selecting specific aconitate and polyacrylate for combination can form a good three-component synergistic effect with the chloroprene rubber matrix. Since the polarity of the aconitate is directly related to the alkyl chain on its structure, according to the principle of similar compatibility of polarities, within the range from tributyl aconitate to tri-n-octyl aconitate or tris(2-ethylhexyl) aconitate, it can have good compatibility with polyacrylate and chloroprene rubber. In addition, the glass transition temperature of polyacrylate is also closely related to the length of its ester group chain. When the number of carbon atoms in the ester group chain is 4 - 8, it can achieve a better low-temperature modification effect on chloroprene rubber. Description of the Drawings

[0025] The drawings described herein are used to provide a further understanding of the present application and form a part of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation to the present application. In the drawings: Figure 1 It is a result diagram showing that the aconitate in Example 1 of the present application makes the glass transition temperatures of the two materials coincide; Figure 2 It is a result diagram showing the change in mechanical properties of the material before and after aging in Example 1 of the present application; Figure 3 It is a GPC spectrum diagram of isooctyl acrylate in Example 1 of the present application; Figure 4 It is a GPC spectrum diagram of n-butyl acrylate in Example 2 of the present application; Figure 5This is the GPC spectrum of n-hexyl polyacrylate involved in Example 3 of this application. Detailed implementation mode

[0026] The embodiments of this application are described in detail below. However, this application is not limited to these embodiments. Unless otherwise specified, the raw materials and catalysts in the embodiments of this application are all purchased through commercial channels. Among them, aconitic acid ester is purchased from Chengdu Camel Pharmaceutical Technology Co., Ltd.; chloroprene rubber CR321 is purchased from Jinan Dahui Chemical Industry, chloroprene rubber CR122 is purchased from Shanxi Synthetic Rubber Co., Ltd., and chloroprene rubber CR244 is purchased from Shanxi Synthetic Rubber Co., Ltd.; polyacrylate is purchased from Shanghai Merck Chemical Technology Co., Ltd.; stearic acid is purchased from Langfang Pengcai Fine Chemicals; magnesium oxide is purchased from Jiangsu Zehui Magnesium-based New Materials Technology; zinc oxide is purchased from Weifang Aolong Zinc Industry. The molecular weight range of the polyacrylate used in this application can be 10,000 - 200,000 g / mol, and the preferred range is 20,000 - 100,000 g / mol. As Figures 3 to 5 shown, they are the GPC spectra of isooctyl polyacrylate, n-butyl polyacrylate, and n-hexyl polyacrylate used in Examples 1 - 3 respectively, and the average molecular weights are 47,968 g / mol, 97,473 g / mol, and 19,343 g / mol respectively.

[0027] It should be noted that in the solution of this application, in order to test the performance of the aging-resistant low-temperature chloroprene rubber composition, the vulcanization process includes: uniformly cutting a 145 mm × 122 mm × 2 mm sample piece from the mixed rubber sample, and vulcanizing it for 15 minutes under the conditions of a vulcanization pressure of 10 Mpa and a vulcanization temperature of 150 °C. After vulcanization, take out the sample piece and park it in room-temperature water for 15 minutes, drain the water, and use it after parking for 3 hours.

[0028] Example 1 In this example, the basic formula of the aging-resistant low-temperature chloroprene rubber composition consists of the following components by weight: 100 parts of chloroprene rubber CR321, 25 parts of tributyl aconitate, 15 parts of isooctyl polyacrylate, 1.5 parts of stearic acid, 4 parts of magnesium oxide, and 5 parts of zinc oxide; The preparation process of this aging-resistant low-temperature chloroprene rubber composition includes the following steps: 1) Weigh CR321, tributyl aconitate, and isooctyl polyacrylate and add them to an open mill. Set the mixing temperature to 45 °C and the mixing time to 3 minutes; 2) Weigh stearic acid and add it to the open mill. Set the mixing temperature to 45 °C and the mixing time to 3 minutes; Slowly add magnesium oxide and zinc oxide along the roller. Set the mixing temperature to 45 °C and the mixing time to 5 minutes to ensure that magnesium oxide and zinc oxide are completely mixed; Make 3 / 4 cutters from each side alternately 2 times; Adjust the roller distance to 0.8 mm and thin-pass the mixed rubber longitudinally in a roll 4 times to obtain the aging-resistant low-temperature chloroprene rubber composition.

[0029] Example 2 In this example, the basic formulation of the aging-resistant low-temperature neoprene rubber composition consists of the following components by weight: 100 parts of neoprene CR122, 10 parts of tri-n-octyl aconitate, 20 parts of n-butyl acrylate, 1 part of stearic acid, 1 part of magnesium oxide, and 10 parts of zinc oxide; The preparation process of the aging-resistant low-temperature neoprene rubber composition includes the following steps: 1) Weigh CR122, tri-n-octyl aconitate, and n-butyl acrylate and add them to an open mill. Set the mixing temperature to 50 °C and the mixing time to 2 min; 2) Weigh stearic acid and add it to the open mill. Set the mixing temperature to 50 °C and the mixing time to 2 min; Slowly add magnesium oxide and zinc oxide along the roller. Set the mixing temperature to 50 °C and the mixing time to 3 min to ensure that magnesium oxide and zinc oxide are completely mixed; Make 3 / 4 cutters alternately from each side 3 times; Adjust the roll gap to 0.8 mm and roll the mixed rubber into a coil and thin it longitudinally 6 times to obtain the aging-resistant low-temperature neoprene rubber composition.

[0030] Example 3 In this example, the basic formulation of the aging-resistant low-temperature neoprene rubber composition consists of the following components by weight: 100 parts of neoprene CR244, 30 parts of tri-n-hexyl aconitate, 10 parts of n-hexyl acrylate, 2 parts of stearic acid, 10 parts of magnesium oxide, 1 part of zinc oxide, and 2.5 parts of thiourea accelerator NA-22; The preparation process of the aging-resistant low-temperature neoprene rubber composition includes the following steps: 1) Weigh CR244, tri-n-hexyl aconitate, and n-hexyl acrylate and add them to an open mill. Set the mixing temperature to 55 °C and the mixing time to 1 min; 2) Weigh stearic acid and add it to the open mill. Set the mixing temperature to 55 °C and the mixing time to 1 min; Slowly add magnesium oxide, zinc oxide, and NA-22 along the roller. Set the mixing temperature to 55 °C and the mixing time to 2 min to ensure that magnesium oxide, zinc oxide, and NA-22 are completely mixed; Make 3 / 4 cutters alternately from each side 6 times; Adjust the roll gap to 0.8 mm and roll the mixed rubber into a coil and thin it longitudinally 8 times to obtain the aging-resistant low-temperature neoprene rubber composition.

[0031] Comparative Example 1 Compared with Example 1, this comparative example is different in that it does not contain tri-n-butyl aconitate and isooctyl acrylate.

[0032] Comparative Example 2 Compared with Example 1, this comparative example is different in that it does not contain tri-n-butyl aconitate.

[0033] Comparative Example 3 This comparative example is different from Example 1 in that it does not contain isooctyl acrylate.

[0034] Comparative Example 4 This comparative example is different from Example 1 in that the aconitate is replaced with an equal amount of phthalate (DOP).

[0035] Test Example 1 The experimenters vulcanized the chloroprene rubber compositions prepared in Examples 1-3 and Comparative Examples 1-4, and tested their aging resistance, low-temperature resistance, and plasticizing properties. The test items included: 1) Low-temperature brittleness temperature, tested according to GB / T 15256-2014 "Determination of Low-temperature Brittleness of Vulcanized Rubber or Thermoplastic Rubber (Multiple Specimen Method)". The low-temperature brittleness temperature can characterize the cold resistance of the material. The lower the brittleness temperature, the better the cold resistance of the material; 2) Hardness, according to GB / T 531-2008 "Indentation Hardness Test Method, Shore Hardness Tester Method". Hardness can characterize the plasticizing properties of the material. The smaller the value, the better the plasticizing effect; 3) 500% modulus at 100% elongation, according to GB / T 1040–2006 "Plastics - Determination of Tensile Properties". The tensile speed was 50 mm / min and the temperature was 25°C. The 500% modulus at 100% elongation can characterize the plasticizing properties of the material. The smaller the value, the better the plasticizing effect; 4) Aging performance, according to GB / T 3512-2014 "Vulcanized Rubber or Thermoplastic Rubber - Heat Aging and Heat Resistance Tests". The test time was 72 h and the temperature was 100°C. After aging, the hardness, tensile strength, elongation at break, and 500% modulus at 100% elongation of the test material were tested. Among them, the tensile strength was tested according to GB / T 1040–2006 "Plastics - Determination of Tensile Properties". The tensile speed was 50 mm / min and the temperature was 25°C. The tensile strength can characterize the strength of the material. The larger the value, the higher the material strength. Among them, the elongation at break was tested according to GB / T 1040–2006 "Plastics - Determination of Tensile Properties". The tensile speed was 50 mm / min and the temperature was 25°C. The elongation at break can characterize the toughness of the material. The higher the elongation at break, the stronger the toughness.

[0036] Among them, in the aging performance test, the calculation formula for the change rate of performance is P = (X a - X 0 ) / X 0 , where P is the change rate of performance, in %, X 0 is the performance value before aging, X a is the performance value after aging. The calculation formula for the hardness change is H = X a - X 0 , where H is the hardness change, X 0 is the hardness before aging, X a is the hardness after aging. The greater the change in the material performance after aging, the worse the aging performance, that is, the worse the heat resistance.

[0037] The test results are shown in Table 1 below. Among them, the test results of the elongation at break in the aging performance test of Example 1 are as Figure 2 shown.

[0038] Table 1

[0039] According to Comparative Example 1 and Comparative Example 2, it can be seen that adding polyacrylate can improve the toughness and cold resistance of chloroprene rubber to a certain extent. However, limited by poor compatibility, the improvement amplitude is not large.

[0040] According to Comparative Example 3, adding tributyl aconitate can improve the cold resistance of chloroprene rubber, and the low-temperature brittleness temperature drops from -38°C to -47°C. Adding tributyl aconitate can improve the cold resistance of chloroprene rubber, but the aging resistance of the obtained chloroprene rubber shows an obvious downward trend. The reason is that the intermolecular interaction force between tributyl aconitate and chloroprene rubber is small, and tributyl aconitate is easy to migrate to the outside at high temperature, resulting in poor aging resistance of the material.

[0041] Compared with Examples 1 to 3, Comparative Example 4 has problems of unremarkable plasticizing effect and poor aging resistance when using DOP as a plasticizer compared with the technical solution of the present application. The chloroprene rubber composition prepared in the present application not only has excellent cold resistance but also has excellent aging resistance, successfully solving the problem of the decline in anti-aging performance caused by adding aconitate to improve cold resistance in the current prior art.

[0042] In the examples of the present application, by introducing polyacrylate, on the one hand, aconitate can make polyacrylate and chloroprene rubber completely compatible, improving the modification effect; at the same time, aconitate exists between chloroprene rubber and polyacrylate, and has a stronger intermolecular interaction force with the blended matrix material, which can effectively reduce the outward migration of aconitate and improve the thermal stability and aging resistance of the material.

[0043] After blending the three in a certain proportion, aconitate can make polyacrylate and chloroprene rubber completely compatible by virtue of its good compatibility with the two materials, improving the increase of polyacrylate in the cold resistance and toughness of chloroprene rubber, and solving the problem of the decline in anti-aging performance caused by adding aconitate to improve cold resistance. Especially in terms of cold resistance, aconitate not only improves the low-temperature brittleness of chloroprene rubber but also increases the modification of the low-temperature performance of chloroprene rubber by polyacrylate, making the chloroprene rubber composite have better cold resistance, and the low-temperature brittleness temperature is as low as -55°C.

[0044] Experimental Example 1 The experimenters explored the influence of the addition types of polyacrylate and aconitate on the performance and found that when polyacrylates in the range from n-butyl acrylate to n-octyl acrylate or isooctyl acrylate were combined with aconitates in the range from tributyl aconitate to trioctyl aconitate or tris(2-ethylhexyl) aconitate, it was possible to more effectively reduce the decline in aging resistance performance caused by the high-temperature volatilization of aconitates. The prepared chloroprene rubber composition had good aging resistance and cold resistance properties.

[0045] The samples in Table 2 and Table 3 below were prepared in the same way as in Example 1, except that the types of polyacrylate or aconitate used were different. The performance detection method was the same as in Test Example 1. The specific differences between Samples 1-4 and Example 1 are shown in Table 2 below.

[0046] Table 2

[0047] Table 3

[0048] According to the test results in Table 3, from the results of Sample 1, it can be seen that when the polyacrylate is n-ethyl acrylate, its low-temperature resistance becomes poor because the glass transition temperature of n-ethyl acrylate is not below -40 °C and it cannot improve the low-temperature resistance performance. At the same time, the test results of Sample 4 show that when n-decyl acrylate and aconitate are selected for use together, chloroprene rubber is incompatible with n-decyl acrylate, so the plasticizing effect on chloroprene rubber is poor. Comparing with Sample 2, it can be seen that when tributyl aconitate is selected, because its molecular weight is too low, the plasticizer is prone to migration, affecting the plasticizing performance, and at the same time, the aging resistance of chloroprene rubber will be greatly reduced. Finally, according to the test results of Sample 3, it can be seen that when trioctyl aconitate is selected, because its molecular chain is too long, it will be incompatible with chloroprene rubber, and at the same time, because the compatibility between polyacrylate and chloroprene rubber is poor, the overall plasticizing effect is not ideal.

[0049] According to the performance test results of Examples 1-3, it can be seen that when tributyl aconitate to trioctyl aconitate and n-butyl acrylate to n-octyl acrylate are selected for combination, it can ensure that the plasticizing effect, cold resistance and aging resistance of chloroprene rubber are all excellent.

[0050] Test Example 2 The experimenters found that the combined use of aconitate and polyacrylate can also improve the compatibility of the ternary components including chloroprene rubber, making it more difficult for polyacrylate and aconitate to separate from the ternary components, thereby improving the strength of the performance improvement of polyacrylate and aconitate. The experimenters detected the glass transition temperature (T g), the glass transition temperature was tested by a dynamic mechanical analyzer. The test conditions included using nitrogen as the carrier gas, with a test temperature range of -40 to -80 °C, a heating rate of 3 °C / min, and a frequency of 1 Hz. The glass transition temperature can characterize the compatibility of materials. If two materials are completely incompatible, there are two T g and each T g is the same as the T g of a single substance; if two materials are partially compatible, there are two T g and the two T g approach each other compared to the T g of a single substance; if two materials are completely compatible, there is only one T g , and it is located between the two T g of single substances.

[0051] The test results of the glass transition temperature are shown in Table 4 below.

[0052] Table 4

[0053] According to the results in Table 4, when polyethyl acrylate and tributyl aconitate are selected for Sample 1, the compatibility of the three is good. However, due to the relatively high glass transition temperature of polyethyl acrylate, the improvement effect on the cold resistance of chloroprene rubber is poor; when triethyl aconitate and isooctyl acrylate are selected for Sample 2, because the glass transition temperature of isooctyl acrylate is below -50 °C, to a certain extent, it can improve the cold resistance of chloroprene rubber. However, due to the relatively short molecular chain of triethyl aconitate, the aging resistance of the chloroprene rubber composition is poor when the three are combined; for Samples 3 and 4, two glass transition temperatures are detected, indicating that when the molecular chain of aconitate or polyacrylate is too long, the compatibility of the three will become poor, and since aconitate is a small molecule substance, the glass transition temperature cannot be measured.

[0054] As described above, the above are only the embodiments of the present application. The protection scope of the present application is not limited by these specific embodiments, but is determined by the claims of the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the technical idea and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An aging-resistant low-temperature chloroprene rubber composition, characterized in that: The invention comprises the following components by weight: 100 parts of chloroprene rubber, 10-30 parts of aconitate, 10-20 parts of polyacrylate, 1-2 parts of stearic acid, 1-10 parts of magnesium oxide and 1-10 parts of zinc oxide.

2. The aging-resistant low-temperature chloroprene rubber composition according to claim 1, characterized in that: The aconitate ester is selected from one or more of tri-n-butyl aconitate, tri-n-pentyl aconitate, tri-n-hexyl aconitate, tri-n-heptyl aconitate, tri-n-octyl aconitate or tri(2-ethylhexyl) aconitate.

3. The aging-resistant low-temperature chloroprene rubber composition according to claim 1, characterized in that: The polyacrylate is selected from one or more of poly(n-butyl acrylate), poly(n-pentyl acrylate), poly(n-hexyl acrylate), poly(n-heptyl acrylate), poly(n-octyl acrylate) or poly(isooctyl acrylate).

4. The aging-resistant low-temperature chloroprene rubber composition according to claim 1, characterized in that: The chloroprene rubber is selected from one or more of sulfur-adjusted type, non-sulfur-adjusted type and mixed-adjusted type.

5. The aging-resistant low-temperature chloroprene rubber composition according to claim 4, characterized in that: When the chloroprene rubber is selected from the non-sulfur regulated type or the mixed regulated type, it also includes a thiourea accelerator. Optionally, the thiourea accelerator is selected from one or more of NA-22, DETU, and DPTU.

6. The aging-resistant low-temperature chloroprene rubber composition according to claim 1, characterized in that: The invention comprises the following components by weight: 100 parts of chloroprene rubber, 25 parts of aconitate, 15 parts of polyacrylate, 1.5 parts of stearic acid, 4 parts of magnesium oxide and 5 parts of zinc oxide.

7. A method for preparing the aging-resistant low-temperature chloroprene rubber composition according to any one of claims 1 to 6, characterized in that: The preparation method comprises the following steps: 1) Weigh chloroprene rubber, aconitate and polyacrylate and add them into an open mixer. Mix at 45-55°C for 1-3 minutes. 2) Weigh stearic acid and add it to the open mixer, the mixing temperature is 45~55℃, and the mixing time is 1~3min; 3) Weigh magnesium oxide and zinc oxide, add magnesium oxide and zinc oxide along the roller, mix at 45~55℃, mix for 2~5min; 4) Alternately make 3 / 4 cuts from each side 2 to 6 times; 5) The roller distance is adjusted, and the mixed rubber is rolled and thinned longitudinally for 4 to 8 times to obtain the aging-resistant low-temperature chloroprene rubber.

8. The preparation method according to claim 7, characterized in that: The preparation method comprises the following steps: 1) Weigh chloroprene rubber, aconitate and polyacrylate and add them into an open mixer at a mixing temperature of 50°C for 1 min. 2) Weigh stearic acid and add it into the open mixer, mix at 50℃ and mix for 1min; 3) Weigh magnesium oxide and zinc oxide, add magnesium oxide and zinc oxide along the roller, mix at 50°C, mix for 2 minutes; 4) Make 3 / 4 cuts from each side three times alternately; 5) The roller distance is adjusted, and the mixed rubber is rolled and thinned longitudinally for 6 times to obtain the aging-resistant low-temperature chloroprene rubber.

9. The preparation method according to claim 7 or 8, characterized in that: The vulcanization method of the aging-resistant low-temperature chloroprene rubber comprises: vulcanizing the mixed rubber sample for 10 to 20 minutes under the conditions of a vulcanization pressure of 10 to 20 MPa and a vulcanization temperature of 140 to 180° C.

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